Cluster-based sensor assignment

ABSTRACT

The logic of a handheld controller system may use a clustering algorithm to determine which sensors of a touch sensor array, such as capacitive pads, to assign to individual fingers of a user&#39;s hand. The clustering algorithm disclosed herein allows for dynamically determining the controller configuration on-the-fly for a given user. An example process includes receiving data generated by a plurality of sensors of a touch sensor array of the handheld controller, generating a covariance matrix that indicates correlations between pairs of sensors, determining a plurality of feature vectors based at least in part on the covariance matrix, each feature vector corresponding to an individual sensor and describing that sensor&#39;s correlation(s) with one or more other sensors, clustering the feature vectors using a clustering algorithm, and configuring the touch sensor array according to a controller configuration that assigns sensors to respective fingers of a hand.

BACKGROUND

Handheld controllers are used in an array of architectures for providinginput, for example, to a remote computing device. For instance, handheldcontrollers are utilized in the gaming industry to allow players tointeract with a personal computing device executing a gamingapplication, a game console, a game server, and/or the like. Handheldcontrollers may find use in virtual reality (VR) environments and maymimic natural interactions such as grasping, throwing, squeezing, etc.,as much as possible. While current handheld controllers provide a rangeof functionality, further technical improvements may enhance systemsthat utilize handheld controllers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a controller according to an example embodiment of thepresent disclosure, with a hand retainer in an open position.

FIG. 2 depicts the controller of FIG. 1 in an open, palm-up, hand of auser according to an example embodiment of the present disclosure.

FIG. 3 depicts the controller of FIG. 1 in a closed hand of the useraccording to an example embodiment of the present disclosure.

FIG. 4 depicts the controller of FIG. 1 in closed, palm-down, hand ofthe user according to an example embodiment of the present disclosure.

FIG. 5 depicts a pair of controllers according to an example embodimentof the present disclosure, with hand retainers in an open position.

FIG. 6 depicts a touch sensor (or touch sensor array) of the controllerof FIG. 1, according to an example embodiment of the present disclosure.

FIG. 7 depicts an example subset of d reference sensors of the touchsensor array of FIG. 6, the subset of reference sensors usable togenerate a n×d covariance matrix for a set of n sensors, according to anexample embodiment of the present disclosure.

FIG. 8 depicts an example n×d covariance matrix that may be generatedbased on data generated by the touch sensor array, according to anexample embodiment of the present disclosure.

FIG. 9 depicts a spatial dot plot that represents a slice ofd-dimensional space, the spatial dot plot illustrating how a clusteringalgorithm clusters feature vectors that describe sensors of the touchsensor array, according to an example embodiment of the presentdisclosure.

FIG. 10 depicts a controller configuration of the touch sensor of FIG.6, according to an example embodiment of the present disclosure.

FIGS. 11-14 depict example processes for configuring a touch sensor of acontroller according to an example embodiment of the present disclosure.

FIG. 15 illustrates example components of the controller of FIG. 1according to an example embodiment of the present disclosure.

DETAILED DESCRIPTION

Described herein are, among other things, handheld controllers havingtouch-sensitive controls, methods for using outputs of thetouch-sensitive controls, and methods for dynamically adjusting thetouch-sensitive controls based on a hand size and/or grip of a useroperating the handheld controller and using a clustering algorithm todynamically assign certain sensors to certain fingers. In someinstances, the handheld controller described herein may control a remotedevice (e.g., a television, audio system, personal computing device,game console, etc.), to engage in video game play, and/or the like.

The handheld controller may include one or more controls such as one ormore joysticks, trackpads, trackballs, buttons, or other controls thatare controllable by the user operating the handheld controller.Additionally, or alternatively, the handheld controller may include oneor more controls that include a touch sensor (sometimes referred toherein as a “touch sensor array”) configured to detect a presence,proximity, location, and/or gesture of the user on respective controlsof the handheld controller. The touch sensor may comprise a capacitivetouch sensor, a force resistive touch sensor, an infrared touch sensor,a touch sensor that utilizes acoustic soundwaves to detect a presence orlocation of an object, a proximity of an object, and/or any other typeof sensor configured to detect touch input at the handheld controller ora proximity of one or more objects relative to the handheld controller.Additionally, in some instances, the touch sensor may comprisecapacitive pads.

The touch sensor communicatively couples to one or more processors of ahandheld controller (or a handheld controller system including thehandheld controller) to send touch sensor data indicative of touch inputat the one or more processors. The touch sensor data may also indicate acloseness or proximity of one or more fingers relative to the handheldcontroller. The touch sensor data may indicate a location of the touchinput on the handheld controller and/or may indicate a location of thefingers relative to the handheld controller, potentially as they changeover time. For instance, if the fingers of the user hover or aredisposed away from the handheld controller, the touch sensor data mayindicate how extended or close the fingers are with respect to thehandheld controller.

The handheld controller (or a handheld controller system including thehandheld controller) may also include logic (e.g., software, hardware,and/or firmware, etc.) that is configured to receive the touch sensordata and determine the presence of a finger of the user and/or alocation (or “position”) of the finger(s) on the handheld controller(s).For example, in instances where the touch sensor comprises thecapacitive pads, different regions or groups of capacitive pads mayrepresent or correspond to different fingers of the user and the logicmay determine which region(s) and/or group(s) of capacitive pads detecta capacitance. This data may be provided to a game or other applicationfor performing one or more actions at the handheld controller, such as agesture performed by finger(s) touching or in close proximity to thehandheld controller. For instance, the touch sensor data or otherindications may be transmitted to an application executing on a gamingconsole, a remote system, other handheld controller(s), or othercomputing devices, such as a head-mounted displays (HMD). Theapplication may utilize the touch sensor data and/or indications toperform one or more actions, such as generating image data (e.g., avirtual representation) corresponding to a hand of the user and itsposition and/or orientation, which may be a gesture, in some instances.

The logic of the handheld controller (or a computing devicecommunicatively coupled to the handheld controller) may use a clusteringalgorithm to determine which sensors of the touch sensor array, such ascapacitive pads, to assign to individual fingers of the user's hand.This sensor-to-finger mapping that assigns subsets of the sensors toindividual fingers of a hand is sometimes referred to herein as a“controller configuration.” The clustering algorithm disclosed hereinallows for dynamically determining the controller configurationon-the-fly for a given user. Cluster analysis is concerned withreceiving a set of samples as input, each sample being described by aset of values (e.g., a multi-dimensional feature vector), and using acluster analysis algorithm to classify the samples into differentgroups. For instance, if a computing device is tasked with classifyingflowers into multiple different species (groups), each flower in thesample set can be described by a set of values (e.g., a feature vector)that include values for: (i) a number of petals, (ii) a color, (iii) anaverage diameter, (iv) a height, etc. In this example, a clusteringalgorithm can analyze the sets of values that describe the sample set,and determine how those sets of values are distributed and correlatedwith each other among the sample set in order to cluster the flowersinto different groups. For instance, a clustering algorithm maydetermine that flowers with five petals tend to be white and tend tohave a first average diameter and height, while flowers with threepetals tend to be yellow and tend to have a second average diameter andheight. Based on these determinations, the samples (in this case,flowers) can be classified into different groups, such as groups thatrepresent a unique species of flower.

In applying cluster analysis to the disclosed touch sensor array of thehandheld controller, the plurality of sensors (e.g., capacitive pads) ofthe touch sensor array may represent a sample set including samples thatare to be classified into one of multiple different groups. At leastsome of these groups may correspond to a respective finger(s) of a hand(e.g., a pinky finger, a ring finger, a middle finger, and possibly anindex finger). In some embodiments, the multiple different groups mayfurther include a “non-finger” group in which untouched, or seldomtouched, sensors can be clustered.

In an illustrative example, as a user grips the handle of the controllerin different ways (e.g., by grasping the handle, extending a finger(s)away from the handle, etc.) over time, the touch sensor array of thehandheld controller generates data, such as capacitance values. Ahistory of data generated by the touch sensor array can be maintainedfor a period of time. The logic of the handheld controller (or acomputing device communicatively coupled to the handheld controller) mayprocess the touch sensor data to generate a covariance matrix, such as an×d covariance matrix for a set of n sensors of the touch sensor array.This covariance matrix describes, or indicates, correlations betweenpairs of sensors. In other words, the covariance matrix indicates whichsensors (e.g., capacitive pads) vary with each other over time, and,conversely, which sensors do not vary with each other over time. In someembodiments, in order to generate the covariance matrix, the logic maycalculate statistics based on the history of data generated by the touchsensor array, such as calculating average capacitance values over thelast p samples detected by individual sensors (e.g., capacitive pads).The logic may use the calculated statistics to determine covariancevalues (e.g., a value within a range of negative one to positive one[−1,+1]) that indicate the degree of correlation between pairs ofsensors, and may populate the covariance matrix with these covariancevalues. The n×d matrix may be initially built and continuously updatedwith these covariance values.

Notably, generating a n×d covariance matrix for a set of n sensors,where d<n, allows for generating a covariance matrix with fewerpositions than the number of positions that would be populated in a n×ncovariance matrix. This allows for conserving computing resourcesbecause it is less expensive, from a computational standpoint, togenerate a n×d covariance matrix than it is to generate a n×n covariancematrix, where d<n. It is to be appreciated, however, that d may beequivalent to n, in some embodiments. Furthermore, because the sampleset to be clustered corresponds to an array of sensors that aresubstantially horizontally-striated across the handle of the controller,generating a n×d covariance matrix, where d<n, provides sufficient datato accurately cluster feature vectors that describe the sensors (e.g.,capacitive pads). In other words, it can be assumed, if the user isholding the controller with the correct hand (e.g., holding aleft-handed controller with the left hand, as opposed to holding theleft-handed controller with the right hand) in the correct manner (e.g.,with fingers oriented substantially horizontally on the handle of thecontroller), that certain sensors are highly likely to be positivelycorrelated with each other. For instance, when the controller is heldwith the correct hand, in the correct manner, two adjacent sensors thatare in the same horizontal row and closest to the palm of the hand arehighly likely to be positively correlated with each other because asingle finger is highly likely to cover both sensors when the handle isgrasped, as opposed to the single finger touching one but not the otherof the adjacent sensors. Accordingly, it is to be appreciated that itmay be wasteful, from a computational standpoint, to evaluate whethercertain pairs of sensors are positively correlated if it is highlylikely that they will be positively correlated. Instead, only a subsetpossible permutations of sensors pairs may be evaluated for a positivecorrelation between those pairs of sensors using a n×d covariancematrix, where d<n. Moreover, because the covariance matrix is symmetricwith respect to the principal diagonal of the covariance matrix, thelogic of the handheld controller (or a handheld controller systemincluding the handheld controller) need not calculate values of thecovariance matrix on both sides of the principal diagonal. That is, thelogic may calculate values of the covariance matrix on one side of theprincipal diagonal, and duplicate, or replicate, those values on theother side of the principal diagonal to create the symmetric covariancematrix, thereby conserving computing resources by avoiding calculationof values on one side of the principal diagonal.

Each sensor (e.g., capacitive pad) of the touch sensor array can bedescribed by a d-dimensional feature vector (where d is a positiveinteger that is less than or equal to n) having a set of values that areeach indicative of a degree of correlation between the sensor andanother sensor in the touch sensor array. In an illustrative example,the touch sensor array may include n=32 sensors (e.g., capacitive pads).This array of 32 sensors may be distributed across the handle of thecontroller for tracking the user's fingers on the handle. A subset ofreference sensors, such as a subset of d=5 reference sensors, can beselected, or otherwise used, to generate a 32×5 covariance matrix, in anillustrative example. Thus, in this example, each sensor is described bya five-dimensional (5D) feature vector, resulting in 32 5D featurevectors. In this example, a 5D feature vector for the i^(th) sensor maydescribe the i^(th) sensor's degrees of correlation with a set of fivesensors among the 32 sensors. It is to be appreciated that the number“n” may represent any positive integer. n=32 is merely an example of anumber of sensors (e.g., capacitive pads) that may constitute the touchsensor array.

A clustering algorithm, such as a k-means clustering algorithm, mayprocess the respective sets of values of the d-dimensional featurevectors that describe individual sensors of the set of n sensors tocluster the feature vectors by determining which ones are positivelycorrelated with each other. In this manner, the sensors of the touchsensor array that are described by the clustered feature vectors can beassigned to different groups that make up a controller configuration. Atleast some of these groups may be associated with respective fingers ofthe hand (e.g., a pinky finger, a ring finger, a middle finger, andpossibly an index finger). For example, in a given controllerconfiguration, a first subset of the n sensors may be assigned to afirst group that corresponds to a first finger of the hand (e.g., themiddle finger), a second subset of the n sensors may be assigned to asecond group that corresponds to a second finger of the hand (e.g., thering finger). In some cases, a third subset of the n sensors may beassigned to a third group that corresponds to a third finger (e.g., thepinky finger). As mentioned, in some cases, a fourth subset of the nsensors may be assigned to a fourth group that is not associated withany finger (this group being referred to herein as a “non-finger”group). A non-finger group may be utilized if, for example, it isexpected that a subset of the n sensors will never, or seldom, betouched while the user is holding/using the handheld controller.

The disclosed cluster-based sensor assignment approach is more flexibleand versatile, as compared to traditional approaches for assigningsensors of a touch sensor array to fingers of a hand. This is at leastbecause, in the disclosed cluster-based sensor assignment approach,there is no preconceived notion of controller configurations that mapsensors to fingers, and the controller configurations are therefore notlimited to a predefined set of configurations. Rather, the controllerconfigurations that map sensors to fingers are determined on-the-flyusing a clustering algorithm. This is an improvement over traditionalapproaches where static controller configurations are used, or where acontroller configuration is selected from a limited set of predefinedcontroller configurations. Both of these traditional approaches may endup utilizing controller configurations which are suboptimal for a givenuser's grip. Furthermore, using the disclosed cluster-based sensorassignment approach also means that the logic is less dependent upon theparticular arrangement of the sensors (e.g., capacitive pads) in thetouch sensor array. That is, the disclosed cluster-based sensorassignment logic works well with varying arrangements and/ordistributions of sensors on the handle of the controller. This maytranslate into a lower cost of manufacturing the handheld controllerbecause less design work is necessary for arranging the sensors of thetouch sensor array on the handle, and/or it may be utilized across awide range of controller designs.

When the touch sensor array is configured according to a controllerconfiguration based on the clustering described above, and when datafrom the touch sensor array is subsequently received, the logic of thehandheld controller (or a computer communicatively coupled to thehandheld controller) may associate the data generated by the touchsensor array with corresponding fingers of the user, which may in turnbe utilized by (e.g., input to) an application to render a virtual handon a display and/or identify a hand gesture. In other words, knowingwhich sensor(s) (e.g., capacitive pad(s)) correspond to respectivefingers of the hand (sometimes referred to as “finger tracking”) allowsthe logic to determine a corresponding hand gesture of the user, such aswhen fingers grip the handheld controller and/or which fingers do notgrip the handheld controller. For instance, the logic may determine theuser grips the handheld controller with the middle finger and the ringfinger, but not the pinky finger. As such, knowing which sensor(s), orgroup of sensor(s) correspond to the respective fingers of the hand, thelogic may provide an indication of this gesture to an applicationconfigured to perform a predefined action associated with the gesture orgenerate image data corresponding to the hand, and, in some cases, agesture (e.g., middle finger and ring finger grip an object, while thepinky finger does not grip the object). Moreover, through utilizingtouch sensor data associated with a proximity of the fingers relative tothe handheld controller, such as detected capacitance values, the logicof the handheld controller may determine an amount of curl or extensionassociated with each finger (e.g., how far the fingers are disposed awayfrom handheld controller).

The handheld controller may dynamically adjust, detect, and accommodatefor varying grips of the user or different users that operate thehandheld controller. For instance, the grip of the user may changedepending on how the user holds the handheld controller, what game theuser plays, and/or physical features of the hand of the user (e.g.,length of finger, width of finger, etc.). The touch sensor array maytherefore adapt to different grips of the user by using the clusteringalgorithm to dynamically update the controller configuration at runtimeto one that best fits the user's grip. This may include instances wherethe user holds the handheld controller differently, and the touch sensorarray may adapt to the grip of users by reconfiguring the touch sensorarray according to an updated controller configuration. In other words,even for different users with similar hands, or as a user progressesthroughout gameplay, the grip of the user may change (e.g., the fingersof the user may grip different parts of handheld controller). Toaccommodate for the varying grips and to enhance a gameplay experience,the logic may remap or re-associate the sensors (e.g., capacitive pads)of the touch sensor array according to different, dynamically-determinedcontroller configurations. In doing so, the logic of the controller mayassociate the touch sensor data with certain fingers of the user toaccurately portray a virtual hand on a display and/or a hand gesture ofthe user.

The handheld controller may also sense, detect, or measure, via thetouch sensor array and/or a pressure sensor, an amount of forceassociated with touch input at the handheld controller. For instance, asa finger of a user presses against the handheld controller, a portion ofthe controller, such as a cover disposed above the touch sensor arrayand/or the pressure sensor, may deflect to contact the touch sensorand/or the pressure sensor. The pressure sensor may couple to the one ormore processors such that touch input of the finger may result in forcedata being provided to the one or more processors. The pressure sensormay provide force data indicative of an amount of force of the touchinput to the one or more processors. In some instances, the pressuresensor may comprise a force-sensing resistor (FSR) sensor, apiezoelectric sensor, a load cell, a strain gauge, a capacitive-typepressure sensor that measures capacitive force measurements, or anyother type of pressure sensor. Additionally, in some instances, thetouch sensor data and/or the force data may be interpreted together andassociated with a predefined command (e.g., squeezing).

While traditional handheld controllers may include sensors to sensetouch input, many traditional controllers statically map the touchsensor to certain fingers. Such mapping, however, does not reassignportions of the touch sensor array, such as the capacitive pads, tocertain fingers or dynamically adapt the touch sensor array to differentfingers depending on the grip of the user. This static mapping may leadto a user experience within a gameplay environment that is less thanideal. For instance, if the touch sensor data does not accurately map toa respective finger of the user, the generated hand image may notaccurately depict the hand of the user operating the handheldcontroller. Other traditional handheld controllers, while capable ofdynamically switching controller configurations, are limited to a set ofpredefined configurations that are used in an attempt to accommodate auser's grip as best as possible using the predefined controllerconfigurations. However, these predefined controller configurations notbe optimized for the unique grips of certain users. The techniques andsystems described herein improve upon the traditional handheldcontrollers by using a clustering algorithm to dynamically determinewhich sensors (e.g., capacitive pads) of the touch sensor array are tobe assigned to certain fingers of the user's hand. In doing so, thereare many more possible configurations that map sensors (e.g., capacitivepads) to fingers in different ways, making for a much more flexible andversatile finger tracking approach. This, in turn, can enable image datagenerated from touch sensor data to more accurately depict the fingersof the user, which may enrich gameplay experience and/or otherapplications being controlled by the handheld controller.

FIG. 1 is a front view of an example controller 100 that may include oneor more touch-sensitive controls. As will be discussed herein, thetouch-sensitive controls may generate touch sensor data utilized by thecontroller 100 and/or other computing devices to generate hand gesturesof the user. The touch sensor data may indicate a presence, location,closeness, and/or gesture of a finger(s) of a user operating thecontroller 100. In some instances, the controller 100 may be utilized byan electronic system such as a VR video gaming system, robot, weapon, ormedical device.

As illustrated, the controller 100 may include a controller body 110having a handle 112, and a hand retainer 120. The controller body 110may include a head disposed between the handle 112 and a distal end 111of the controller 100, which may include one or more thumb-operatedcontrols 114, 115, 116. For example, a thumb-operated control mayinclude a tilting button, or any other button, knob, wheel, joystick, ortrackball conveniently manipulated by a thumb of a user during normaloperation when the controller 100 is held in the hand of the user.

The handle 112 may include a substantially cylindrical tubular housing.In this context, a substantially cylindrical shape need not haveconstant diameter, or a perfectly circular cross-section.

The handle 112 may include a proximity sensor and/or a touch sensor(sometimes referred to herein as a “touch sensor array”) having aplurality of sensors, such as capacitive pads, spatially distributedpartially or completely on (e.g., around a surface of), or otherwisespread about, the handle 112. An example of this touch sensor array isdepicted in FIG. 6. In an example, the sensors (e.g., capacitive pads)may be spatially distributed beneath the outer surface of the handle 112and/or may be embedded under the outer surface of the handle 112. Thesensors (e.g., capacitive pads) may be responsive to a user touching,gripping, or grasping the handle 112 to identify the presence, position,and/or gestures of one or more fingers of the user. Additionally, thesensors (e.g., capacitive pads) may be responsive to one or more fingershovering or being disposed above the handle 112. For instance, one ormore fingers of the user may not grasp or wrap around the controller 100but instead, may be displaced above the outer surface of the handle 112.To accommodate such and detect a proximity of the fingers and/or touchinput, the outer surface of the handle 112 may comprise an electricallyinsulative material.

The hand retainer 120 may couple to the controller 100 to bias the palmof the hand of the user against the outside surface of the handle 112.As shown in FIG. 1, the hand retainer 120 is in the open position. Thehand retainer 120 may optionally bias in the open position by a curvedresilient member 122 to facilitate the insertion of the hand of the userbetween the hand retainer 120 and the controller body 110 when the usergrasps the controller 100. For example, the curved resilient member 122may include a flexible metal strip that elastically bends, or maycomprise an alternative plastic material such as nylon, that may bendsubstantially elastically. A fabric material 124 (e.g., a sheath made ofcloth, neoprene, or any suitable material), may partially or completelycover the curved resilient member 122 to cushion or increase a comfortof the user. Alternatively, the cushion or fabric material 124 mayadhere to only the side of the curved resilient member 122 facing thehand of the user.

The hand retainer 120 may adjust in length, for example, by including adraw cord 126 that is cinched by a spring-biased chock 128. The drawcord 126 may optionally have an excess length for use as a lanyard. Insome examples, the cushion or fabric material 124 may attach to the drawcord 126. In addition, the curved resilient member 122 may be preloadedby the tension of the cinched draw cord 126 and in such embodiments, thetension that the curved resilient member 122 imparts to the handretainer 120 (to bias it in the open position) may cause the handretainer 120 to automatically open when the draw cord 126 is un-cinched.However, alternative conventional ways to adjust the length of a handretainer 120, such as a cleat, an elastic band (that temporarilystretches when the hand is inserted, so that it applies elastic tensionto press against the back of the hand), a hook & loop strap attachmentthat allows length adjustment, etc. may be used.

The hand retainer 120 may be disposed between the handle 112 and atracking member 130, and may contact the back of the hand of the user.The tracking member 130 may affix to the controller body 110 and mayoptionally include two noses 132, 134, where each nose may protrude froma corresponding one of two opposing distal ends of the tracking member130. In some instances, the tracking member 130 may include an archaving a substantially arcuate shape. In some instances, the trackingmember 130 may include tracking transducers (e.g., sensors or beacons,such as infrared (IR) light sensors or IR light beacons) disposedtherein, for example, with at least one tracking transducer disposed ineach protruding nose 132, 134. The controller body 110 may includeadditional tracking transducers, such as a tracking transducer disposedadjacent the distal end 111.

The controller 100 may include a rechargeable battery disposed withinthe controller body 110, and the hand retainer 120 may include anelectrically-conductive charging wire electrically coupled to therechargeable battery. The controller 100 may also include a radiofrequency (RF) transmitter for communication with the rest of anelectronic system (e.g., a gaming console, which may be a component ofthe handheld controller system). The rechargeable battery may power theRF transmitter and the data transmitted via the RF transmitter may bedata generated in response to operations of the thumb-operated controls114, 115, 116, the touch sensor (e.g., the capacitive sensors) in thehandle 112, and/or tracking sensors in the tracking member 130.

In some instances, the controller body 110 may comprise a single pieceof injection molded plastic or any other material rigid enough totransfer a force from a finger of the user to the touch sensor and thinenough to allow for capacitive coupling between a finger of the user andthe touch sensor. Alternatively, the controller body 110 and thetracking member 130 may be fabricated separately, and then laterassembled together.

FIG. 2 is a front view of the controller 100, showing the controller 100during operation with the left hand of the user inserted therein but notgrasping the controller body 110. In FIG. 2, the hand retainer 120 iscinched over the hand of the user to physically bias the palm of theuser against the outside surface of the handle 112. Here, the handretainer 120, when closed, may retain the controller 100 on, or around,the hand of the user even when the hand is not grasping the controllerbody 110. As shown, when the hand retainer 120 is closed tightly aroundthe hand of the user, the hand retainer 120 may prevent the controller100 from falling out of hand of the user. Hence, in some embodiments,the hand retainer 120 may allow the user to “let go” of the controller100 without the controller 100 actually separating from the hand, beingthrown, and/or dropped to the floor, which may enable additionalfunctionality. For example, if the release and restoration of the usergrasping the handle 112 of the controller body 110 is sensed, therelease or grasping may be incorporated into the game to displaythrowing or grasping objects (e.g., in VR environment). The handretainer 120 may allow such a function to be accomplished repeatedly andsafely. The hand retainer 120 may also prevent fingers of the user fromexcessively translating relative to the touch sensor array distributedabout the handle 112 to more reliably sense finger motion and/orplacement on the handle 112.

FIGS. 3 and 4 depict the controller 100 during operation when the handretainer 120 is cinched while the hand of the user grasps the controllerbody 110. As shown in FIGS. 3 and 4, the thumb of the user may operateone or more of the thumb-operated controls 114, 115, 116.

FIG. 5 illustrates that in certain embodiments, the controller 100 maybe the left controller in a pair of controllers that includes a similarright controller 500. In certain embodiments, the controller 500 may bethe right controller in a pair of controllers that includes a similarleft controller 100. In certain embodiments, the controllers 100 and 500may (together) track the motion and grip of both of the hands of theuser, simultaneously, for example, to enhance a VR experience. It is tobe appreciated that reference numeral 100, when used throughout thisdisclosure may be replaced with reference numeral 500 to describe eitherthe left or right controller shown in FIG. 5, without changing the basiccharacteristics of the disclosure.

FIG. 6 illustrates a proximity sensor or a touch sensor 600 (sometimesreferred to herein as a “touch sensor array 600”) having a plurality ofsensors 602 (e.g., capacitive pads 602) configured to detect touch inputon a controller (e.g., the controller 100) as well as a proximity of oneor more objects (e.g., finger) relative to the controller 100. In someembodiments, the touch sensor 600 may additionally or alternativelyinclude different types of sensors than capacitive pads, which areconfigured to detect touch input at the controller 100 or a proximity ofa finger(s) relative to the controller 100, such as an infrared oracoustic sensor(s). It is to be appreciated that references herein to“capacitive pads 602” may be replaced with “sensors 602”, whereappropriate, to describe the touch sensor array 600 with respect to anysuitable type of sensor technology. As shown in FIG. 6, the capacitivepads 602 of the touch sensor 600 are arranged in an array, but thecapacitive pads 602 are not necessarily of equal size and do notnecessarily have substantially equal spacing therebetween. However, insome embodiments, the capacitive pads 602 may comprise a grid, withsubstantially equally spacing therebetween, and of substantially equalsize.

The touch sensor 600 may include a flexible printed circuit assembly(FPCA) 604 on which the capacitive pads 602 are disposed. The FPCA 604may include a connector 606 for connecting to a printed circuit board(PCB) of the controller 100 that includes one or more processors. Thecapacitive pads 602 may communicatively connect to the connector 606 viatraces 608 disposed on the FPCA 604. The capacitive pads 602 may providetouch sensor data (e.g., capacitance value) to the one or moreprocessors of the controller 100 (or of a handheld controller systemthat includes the controller 100) via the traces 608 and the connector606. As discussed in more detail herein, the touch sensor data mayindicate the proximity of the finger relative to the controller 100.That is, the touch sensor 600 may measure the capacitance of individualcapacitive pads 602, where the capacitance may be associated with aproximity of the fingers relative to the controller 100 (e.g., touchingor being disposed above the handle 112 of the controller 100).

The touch sensor 600 may couple to an interior surface within thecontroller body 110, such as a structure mounted within the handle 112of the controller body 110, or a structure mounted underneath the handle112 of the controller body 110. In doing so, touch sensor 600 may bedisposed beneath the outer surface of the handle 112 and configured todetect a proximity of the fingers relative to the handle 112 by virtueof the sensors 602 being distributed about the handle 112. When coupledto the controller 100, the touch sensor 600 may angularly span around acircumference or a portion of the handle 112. For instance, the FPCA 604may couple (e.g., adhesion) to the inner surface of the controller body110 at the handle 112 to detect the proximity of the fingers relative tothe handle 112. In some embodiments, the touch sensor 600 may extend atleast 100 degrees but not more than 170 degrees around the circumferenceof the handle 112. Additionally, or alternatively the touch sensor 600may couple to the outer surface of the controller 110, such as an outersurface of the handle 112.

The capacitive pads 602 may be spaced apart from one another to detect aproximity of different fingers relative to the controller 100, ordifferent portions of the finger(s) of the user (e.g., fingertip). Forinstance, as shown in FIG. 6, the capacitive pads 602 are arranged intorows, columns, a grid, sets, subsets, or groups 610. As will bedescribed in more detail below, when a clustering algorithm is used tocluster feature vectors that describe the individual capacitive pads602, subsets of the capacitive pads 602 may end up being assigned to aparticular finger of the user (e.g., a middle finger, a ring finger, apinky finger, and possibly an index finger) in accordance with adynamically-determined controller configuration.

As shown in FIG. 6, the example touch sensor 600 may include six rows ofcapacitive pads 602, where the rows extend substantially horizontallyacross a surface of the FPCA 604. However, in some embodiments, thetouch sensor 600 may include more than six rows or less than six rows.These rows are oriented substantially horizontally on the handle 112when the touch sensor 600 is integrated into the controller 100.Furthermore, the example touch sensor 600 is shown as including sixcolumns of capacitive pads 602, where the columns extend substantiallyvertically across a surface of the FPCA 604. However, in someembodiments, the touch sensor 600 may include more than six columns orless than six columns. These columns are orientated substantiallyvertically on the handle 112 when the touch sensor 600 is integratedinto the controller 100. The touch sensor 600 may have a set of nsensors 602. The example touch sensor 600 shown in FIG. 6 has a set ofn=32 sensors, because not all rows have an equal number of sensors 602.

When certain subsets of sensors 602 are assigned to groups thatcorrespond to fingers of a hand, the controller 100 (or anothercommunicatively coupled computing device) may utilize touch sensor data(e.g., capacitance values) from the sensors 602 to generate image dataof a virtual hand, such as hand gestures of the user. That is, the touchsensor 600 may generate touch sensor data for use in detecting apresence, location, and/or gesture of the finger(s) of the user thatgrip the controller 100. In embodiments that utilize capacitive-typesensors 602, as the user grips the controller 100 with certain fingersand hovers certain fingers above the controller 100, a voltage isapplied to the capacitive pads 602 that results in an electrostaticfield. Accordingly, when a conductor, such as a finger of a user touchesor nears the capacitive pads 602, a change in capacitance occurs. Thecapacitance may be sensed by connecting an RC oscillator circuit totouch sensor 600 and noting that a time constant (and therefore theperiod and frequency of oscillation) will vary with the capacitance. Inthis way, as a user releases finger(s) from the controller 100, gripsthe controller 100 with certain finger(s), or nears the controller 100,the controller 100 may detect a change in capacitance.

The capacitance values of the capacitive pads 602, or individualcapacitive sensors within a grid on each capacitive pad 602, are used todetermine the location of the conductor as well as the proximity of theconductor relative to the capacitive pad 602. That is, as a user gripsthe controller 100, certain fingers and/or portions of the fingers maycontact the handle 112 of the controller 100. As the finger(s) act as aconductor, those capacitive pads 602 underlying the handle 112 where theuser touches the handle 112 may measure a capacitance value. Thesecapacitance values are measured over time for use in identifying agesture of the user. However, in instances where the user hovers theirfingers or certain portions of their finger away from the controller100, the capacitance value may represent or be associated with how farthe finger is disposed away from the controller 100. The touch sensordata may therefore be utilized to determine the proximity and/orlocation of the fingers with respect to the controller 100. As the gripof the user may change throughout a gameplay experience, or betweendifferent users, it may become beneficial to associate the fingers withdifferent capacitive pads 602 of the touch sensor 600. For example, at afirst instance, a user may have a wide grip and all capacitive pads 602of the touch sensor 600 may detect a capacitance value that can be usedin generating image data associated with a virtual hand. In this firstinstance, certain subsets of the capacitive pads 602 may be assigned tocertain fingers of the hand using a clustering algorithm, as describedherein. At a second instance, the grip of the user may narrow, and lessthan all of the capacitive pads 602 of the touch sensor 600 may detect acapacitance value that can be used in generating the image dataassociated with the virtual hand. In this second instance, because thefingers may touch different capacitive pads 602, as compared to thefirst instance, different subsets of the capacitive pads 602 may beassigned to the fingers of the hand using the clustering algorithm withthe updated touch sensor data. Thus, in order to generate accurate imagedata depicting the hand (e.g., a hand gesture), the capacitive pads 602may be dynamically assigned to certain fingers of the hand using thedisclosed cluster-based sensor assignment approach. Knowing whichcapacitive pads 602 of the touch sensor 600 are associated withrespective fingers of the hand allows for the generation of acorresponding hand gesture using the capacitance values detected by thetouch sensor 600. Therefore, with a changing grip of the user, thecapacitive pads 602 may regroup or associate with different fingers suchthat their capacitance values produce accurate image data depicting ahand gesture.

The one or more processors may include algorithms and/ormachine-learning techniques embodying anatomically-possible motions offingers, to better use the touch sensor data to detect the opening thehand of a user, finger pointing, or other motions of fingers relative tothe controller 100 or relative to each other. In this way, the movementof the controller 100 and/or fingers of the user may help control a VRgaming system, defense system, medical system, industrial robot ormachine, or another device. In VR applications (e.g. for gaming,training, etc.), the touch sensor data may be utilized to render therelease of an object based on the sensed release of the fingers of theuser from the outer surface of the handle 112. Additionally, oralternatively, one or more processors of a communicatively coupledcomputing device (e.g., a host computing device, a game console, etc.)that the controller 100 is interacting with may detect the gesture(s)using the touch data.

In some instances, the capacitive pads 602 may also detect a capacitancevalue that corresponds to an amount of force applied to an associatedportion of the controller 100 (e.g., a force applied to an outer surfaceof the handle 112, to at least one thumb-operated control 114, 115, 116,etc.). Additionally, or alternatively, the touch sensor 600, or otherportions of the controller 100 (e.g., the handle 112), may include aforce sensing resistor (FSR), which uses variable resistance to measurean amount of force applied to the FSR. As the controller 100 may beconfigured to be held by a hand of a user, the FSR may mount on a planarsurface of a structure within the controller body 110, such as astructure that is mounted within the handle 112 of the controller body110, or a structure that is mounted underneath the controller body 110.In certain embodiments, the FSR, in conjunction with the capacitive pads602, may facilitate sensing of both the onset of grasping by the user,and the relative strength of such grasping by the user, which may befacilitate certain gameplay features. In either instance, the FSR maygenerate force data for use in detecting a presence, location, and/orgesture of the finger(s) of the user that grasp the controller 100. Whenimplemented in the controller 100, the FSR and/or the capacitive pads602 may measure a resistance value, or a capacitance value,respectively, that correspond to an amount of force applied to anassociated portion of the controller 100.

In some embodiments, the one or more processors of the controller 100may utilize the touch sensor data and/or the force data to detect a handsize of a hand grasping the handle 112 and/or to adjust the thresholdforce required for registering a touch input at the capacitive pads 602and/or the FSR according to the hand size. This may be useful for makingforce-based input easier for users with smaller hands (and harder, butnot difficult, for users with larger hands).

FIG. 7 depicts an example subset of d reference sensors of the touchsensor array 600 of FIG. 6, the subset of reference sensors usable togenerate a n×d covariance matrix for a set of n sensors, according to anexample embodiment of the present disclosure. That is, in FIG. 7, the“shaded-in” capacitive pads 602 represent subset of d reference sensors.Accordingly, in the example of FIG. 7, d=5, but it is to be appreciatedthat d can be any integer less than or equal to n, n representing thetotal number of sensors 602 in the touch sensor array 600. As mentioned,the touch sensor array 600 may include a plurality of sensors 602 (e.g.,capacitive pads 602) distributed in rows and columns. For example, thesensors 602 may be distributed in a first row 702, a second row 704, athird row 706, a fourth row 708, a fifth row 710, and a sixth row 712.The sensors 602 may also be distributed in a first column 714, a secondcolumn 716, a third column 718, and fourth column 720, a fifth column722, and a sixth column 724. Again, it is to be appreciated that,although the distribution may be in rows and columns, the sensors 602are not necessarily of equal size and do not necessarily havesubstantially equal spacing therebetween. Furthermore, the rows andcolumns do not have to be in perfect alignment (e.g., the rows and/orcolumns may have a slight curve, the sensors 602 can be staggered fromrow-to-row, column-to-column, etc.). In the example of FIG. 7, thesubset of d reference pads (i.e., the “shaded-in” pads 602) comprises acolumn of pads 602, such as the fourth column 720 of pads 602 that isnear a middle of the touch sensor array 602. Choosing the reference padsas a column near a middle of the touch sensor array 602 may allow forevaluating correlations between pairs of sensors 602 where the certaintyof there being a positive correlation between those sensor pairs is notalready known to be highly likely or highly unlikely. This may be basedon heuristics or empirical evidence.

FIG. 8 depicts an example n×d covariance matrix 800 that may begenerated based on data generated by the touch sensor array 600,according to an example embodiment of the present disclosure. Over time,as data is generated by the plurality of sensors 602 of the touch sensorarray 600, this touch sensor data may be processed to generate acovariance matrix, such as the example n×d covariance matrix 800 shownin FIG. 8, where the number “n” represents the number of sensors 602 inthe touch sensor array 600 and “d” represents a set of referencesensors, such as the “shaded-in” sensors 602 shown in FIG. 7. In thisexample, d<n, but it is to be appreciated that the set of d referencesensors may not be a subset if d=n. In an illustrative example, n=32 andd=5.

In general, the covariance matrix 800 indicates correlations betweenpairs of sensors 602 of the plurality of sensors 602 of the touch sensorarray 600. In some embodiments, in order to generate the covariancematrix 800, logic of the handheld controller 100 (or logic of a handheldcontroller system that includes the controller 100) may calculatestatistics based at least in part on the touch sensor data generated bythe touch sensor 600 over a period of time. For example, statistics canbe calculated based on the history of data generated by the touch sensorarray 600, such as calculating average capacitance values over the lastp samples detected by individual sensors (e.g., capacitive pads). Thelogic may use the calculated statistics to determine covariance valuesthat indicate the degree of correlation between pairs of sensors 602,and then the logic may populate the covariance matrix 800 with thesecovariance values. The covariance values that are populated in thevarious positions of the covariance matrix 800 may be values within arange of negative one (−1) to positive one (+1), inclusive, negative onebeing the least positively correlated, and positive one being the mostpositively correlated. The covariance values may be values within otherpossible ranges, such as a range from zero (0) to positive one (+1).Thus, the covariance value that is populated in a given position of thecovariance matrix 800 indicates the degree of correlation between a pairof sensors 602 in terms of whether they vary with each other over time.As touch sensor data is continuously generated by the touch sensor array600, the n×d covariance matrix 800 may be initially built andcontinuously updated with these covariance values over time. Toillustrate, a covariance value at position (i, j) of the covariancematrix 800 may indicate the degree of correlation between i^(th) sensor602 and the j^(th) sensor 602.

The dots 802 shown in the covariance matrix 800 are to indicate examplepairs of sensors 602 that might be positively correlated with eachother, according to the covariance value for that pair of sensors 602.For example, if the covariance value in the i, j position of thecovariance matrix 800 satisfies a threshold value, the i^(th) sensor 602may be considered to be positively correlated with the j^(th) sensor602, and vice versa. As shown by the dots 802 in FIG. 8, the covariancematrix 800 is symmetric with respect to the principal diagonal of thecovariance matrix 800, as is the case with every covariance matrix. Thelogic of the handheld controller 100 (or a handheld controller systemincluding the handheld controller 100) can leverage this property of thecovariance matrix 800 by calculating values of the covariance matrix 800on one side of the principal diagonal, and by duplicating, orreplicating, those values on the other side of the principal diagonal tocreate the symmetric covariance matrix 800, thereby conserving computingresources by avoiding calculation of values on one side of the principaldiagonal.

Based at least in part on the covariance matrix 800, logic of thehandheld controller 100 (or a handheld controller system that includesthe handheld controller 100) may determine a plurality of featurevectors. For a n×d covariance matrix 800, the logic may determine nd-dimensional feature vectors. In an example where n=32, and where d=5,the logic may determine 32 5D feature vectors. Each feature vector maycorrespond to a sensor 602 of the plurality of sensors 602 of the touchsensor array 600. Furthermore, each feature vector may describe acorrelation between the sensor 602 and one or more other sensors 602 ofthe plurality of sensors 602. Where d=5, this means that a given featurevector describes correlations between a given sensor 602 and a set offive sensors 602 of the touch sensor array 600, which correspond to theset of d reference sensors. Thus, a feature vector that describes thetop left sensor 602 in the array may include a first covariance valueindicative of the correlation between the top left sensor 602 and afirst sensor of the set of d reference sensors (e.g., the “shaded-in”references sensors shown in FIG. 7), a second covariance valueindicative of the correlation between the top left sensor 602 and asecond sensor of the set of d reference sensors, and so on for anynumber of d reference sensors. For example, a 5D feature vector for agiven sensor 602 may look like the following: [0, 0, 0.5, 0.8, −0.2]. Itis to be appreciated that a correlation matrix populated withcorrelation values can be used in a similar manner to that describedherein with respect to a covariance matrix 800 populated with covariancevalues. In the case of a correlation matrix, the feature vectors mayinclude correlation values instead of covariance values.

With a plurality of feature vectors derived from the covariance matrix800, a clustering algorithm may be used to cluster the plurality offeature vectors into multiple clusters that are used to assign certainsensors 602 to certain fingers of the hand. Any suitable clusteringalgorithm can be used. A k-means clustering algorithm is suitable,including standard k-means, weighted k-means, etc. Other types ofclustering algorithms besides k-means may additionally or alternativelybe utilized to cluster representations of the sensors 602 into groups.

FIG. 9 depicts a spatial dot plot 900 that may represent a “slice”(e.g., a two-dimensional (2D) slice) of d-dimensional space, the spatialdot plot 900 illustrating how a clustering algorithm, such as a k-meansclustering algorithm, clusters feature vectors that describe sensors 602of the touch sensor array 600, according to an example embodiment of thepresent disclosure. The spatial dot plot 900 may have a vertical axisand a horizontal axis that intersect at a origin, or zero, point. Datapoints 904(1), 904(2), 904(3), . . . , 904(n) represent the featurevectors derived from the covariance matrix 800. In an illustrativeexample, a set of n=32 feature vectors may be derived from a n×dcovariance matrix 800, where d=5, and the data points 904(1)-(n) in thespatial dot plot 900 may represent those feature vectors, each vectorbeing a 5D feature vector corresponding to an individual sensor 602, andwhich describes that sensor's 602 respective degrees of correlation with(or the sensor's 602 covariance to) a subset of d=5 reference sensors.One may think of these feature vectors as pointing to positions inspace, the same way that humans do with 2D or 3D vectors, but in thiscase, the feature vectors may be higher-dimensional vectors that can bevisualized with a slice of that higher-dimensional space. If one were toplot all of the feature vectors in 5D space (the spatial dot plot 900representing a slice of this 5D space), subsets of the feature vectorscan be clustered together in the 5D space using a clustering algorithm,such as a k-means clustering algorithm, to create clusters 906. Eachcluster 906 corresponds to a group that is to be used for fingertracking. For example, a first cluster 906(1) may correspond to a firstgroup associated with a first finger of a hand (e.g., a middle finger),a second cluster 906(2) may correspond to a second group associated witha second finger of the hand (e.g., a ring finger), a third cluster906(3) may correspond to a third group associated with a third finger ofthe hand (e.g., a pinky finger), and, in some cases, a fourth cluster906(4) may correspond to a fourth group that is not associated with anyfinger (e.g., a non-finger group).

Using a k-means clustering algorithm as an example, the clusteringalgorithm may be initialized (or seeded) with input parameters thatinclude, without limitation, a number of k clusters 906, and k centerestimates 908 that represent initial estimates for the centers of theclusters 906 in d-dimensional space. In the example of FIG. 9, thek-means clustering algorithm is initialized with an input parameter ofk=4, but any number of clusters 906 can be specified, and the clusteringalgorithm can be run a subsequent time, or run in the alternative, witha different value of k, such as k=2, k=3, and the like. With k=4, theclustering algorithm tries to cluster the n feature vectors into fourclusters 906 in an optimal way.

FIG. 9 illustrates initial center estimates 908 that include, for k=4, afirst center estimate 908(1), a second center estimate 908(2), and athird center estimate 908(3), and a fourth center estimate 908(4). Thesecenter estimates 908 may be estimated to be reasonably close to theirfinal positions at convergence, which can be based on heuristics orempirical data (e.g., data collected from past use, such as test data,of the handheld controller 100 or a test controller). By makingreasonably good center estimates 908 to initialize the clusteringalgorithm, swapping of cluster centers during execution of the clusteranalysis algorithm is mitigated. In some embodiments, the centerestimates 908 are user-specific based on a known user profile of thehandheld controller 100 (e.g., if a user has logged into a user accountand has used the handheld controller 100 in the past). In anillustrative example, the first center estimate 908(1) for the firstcluster 906(1) may correspond to a group for the middle finger, and maybe estimated as a first point in d-dimensional space (e.g., [0, 0, 0,0.5, 0.5, 0.5]). For instance, the first center estimate 908(1) may beestimated based on a position in d-dimensional space that is correlatedwith a group of sensors 602 positioned higher on the handle 112 of thecontroller 100 (e.g., closer to the head of the controller). Meanwhile,the second center estimate 908(2) for the second cluster 906(2) maycorrespond to a group for the ring finger, and may be estimated as asecond point in d-dimensional space (e.g., [0, 0, 0.5, 0.5, 0, 0]). Forinstance, the second center estimate 908(2) may be estimated based on aposition in d-dimensional space that is correlated with a group ofsensors 602 positioned near the middle of the handle 112 of thecontroller 100. Meanwhile, the third center estimate 908(3) for thethird cluster 906(3) may correspond to a group for the pinky finger, andmay be estimated as a third point in d-dimensional space (e.g., [0, 0,0, 0, 0.5, 0]). For instance, the third center estimate 908(3) may beestimated based on a position in d-dimensional space that is correlatedwith a group of sensors 602 that are positioned lower on the handle 112of the controller 100 (e.g., farther from the head of the controller100). A fourth center estimate 908(4) for the fourth cluster 906(4) maycorrespond to a non-finger group, and may be chosen as the origin 902 ofthe d-dimensional space (e.g., [0, 0, 0, 0, 0, 0]). This fourth centerestimate 908(4) is chosen as the origin 902 based on an expectation thata subset of sensors will not be, or will seldom be, touched during useof the handheld controller 100. As long as these center estimates 908are reasonably accurate (e.g., as long as the center estimates 908 arein the general vicinity of where the cluster center is expected to endup at convergence), the center estimates 908 are sufficient forclustering the feature vectors.

In the process of clustering the feature vectors using a k-meansclustering algorithm that has been initialized with input parameters ofk clusters 906 and center estimates 908 for those k clusters 906, thelogic may iteratively perform an assignment step followed by an updatestep. For the assignment step, the logic may assign each feature vectorto a cluster 906 of the k clusters that has a center estimate 908 thatis a smallest distance from the feature vector. For example, eachfeature vector can be assigned to a cluster 906 whose mean has the leastsquared Euclidean distance. In the example of FIG. 9, data pointsincluding the data point 904(1) are assigned to the cluster 906(1),which has a center estimate 908(1). This is because, for each featurevector assigned to the first cluster 906(1), the distance between thecenter estimate 908(1) and the feature vector is less than any of thedistances between the other center estimates 908(2)-(4) and that featurevector. Said another way, the feature vector represented by the datapoint 904(1) is determined to be closest to the first center estimate908(1), among the k center estimates 908, and, therefore, the featurevector represented by the data point 904(1) is assigned to the firstcluster 906(1) associated with the first center estimate 908(1). Thiscan be done for each feature vector to assign the feature vectors toclusters as part of the assignment step.

For the update step, the logic may update each center estimate 908 toobtain k updated cluster centers 910, where the center estimate 908 fora cluster 906 is updated based at least in part on the feature vectorsassigned to the cluster 906. One way of thinking about this is that thecenter estimates 908 are moved during the update step to the “middle” ofthe subset of feature vectors that have been assigned to thecorresponding cluster 906. Mathematically, this update step may involvecalculating updated means (updated cluster centers 910) of the featurevectors assigned to the cluster 906, and updating the center estimates908 to those updated cluster centers 910. This is depicted in FIG. 9 bythe dashed arrows from the initial center estimates 908 to the updatedcluster centers 910 for each cluster 906. For example, the first centerestimate 908(1) is “moved” to the first updated cluster center 910(1)during the update step, the second center estimate 908(2) is “moved” tothe second updated cluster center 910(2) during the update step, and thethird center estimate 908(3) is “moved” to the third updated clustercenter 910(3) during the update step. The fourth center estimate 908(4)assigned to the origin 902 may not move during the update step. Theassignment step and the update step may iterate until convergence. Thatis, the logic may repeat the assignment step and the update step untilthe updated cluster centers 910 converge to final cluster centers (e.g.,once the assignments no longer change and once the centers 910 for eachcluster 906 cease moving, or move by an amount of zero, or within somethreshold of zero).

At convergence, the feature vectors are clustered, and the touch sensorarray 600 can be configured according to a controller configurationbased at least in part on the clustering. For example, the controllerconfiguration may assign a first subset of sensors 602 that correspondto the feature vectors in the first cluster 906(1) to a first group thatcorresponds to a first finger of a hand (e.g., a middle finger). Thecontroller configuration may also assign a second subset of sensors 602that correspond to feature vectors in the second cluster 906(2) to asecond group that corresponds to a second finger of the hand (e.g., aring finger). The controller configuration may also assign a thirdsubset of sensors 602 that correspond to feature vectors in the thirdcluster 906(2) to a third group that corresponds to a third finger ofthe hand (e.g., a pinky finger). The controller configuration may alsoassign a fourth subset of sensors 602 that correspond to feature vectorsin the fourth cluster 906(4) to a fourth group that corresponds to anon-finger group (e.g., sensors that are not touched, or are seldomtouched.

FIG. 10 depicts a controller configuration 1000 of the touch sensor 600of FIG. 6, according to an example embodiment of the present disclosure.The controller configuration 1000 may have been determined as a resultof the cluster-based sensor assignment techniques described herein,where a covariance matrix 800 is generated to derive feature vectors,and a clustering algorithm, such as a k-means clustering algorithm, isused to cluster the feature vectors, the clusters used to assign sensors602 to groups in accordance with the controller configuration 1000. Asshown in FIG. 10, a first subset 1002(1) of sensors 602 denoted by the“shaded-in” sensors 602 within the bracket 1002(1) may be assigned to afirst group that corresponds to a first finger of a hand (e.g., a middlefinger). A second subset 1002(2) of sensors 602 denoted by the“shaded-in” sensors 602 within the bracket 1002(2) may be assigned to asecond group that corresponds to a second finger of a hand (e.g., a ringfinger). A third subset 1002(3) of sensors 602 denoted by the“shaded-in” sensors 602 within the bracket 1002(3) may be assigned to athird group that corresponds to a third finger of a hand (e.g., a pinkyfinger). Comparatively, the sensors 602 that are not shaded-in representthose sensors that are either assigned to a non-finger group, or thatare assigned to a finger group, but whose capacitance values are notutilized in generating image data corresponding to the gesture of thehand. However, the sensors 602 not shaded-in may still generate touchsensor data (e.g., by measuring or detecting capacitance values) for thepurpose of updating the controller configuration. For instance, if theuser's grip changes and starts to touch one or more of the sensors 602that are not shaded-in, the touch sensor array 600 may be reconfiguredbased on the cluster analysis to an updated controller configurationthat assigns the one or more sensors 602 to a finger group.

Various features can be enabled once sensor assignments have been made.For example, one or more rules can be evaluated once the touch sensorarray 600 has been configured according to a controller configuration tovalidate that the sensor assignments are sensible. For example, logicmay determine whether the subsets 1002 of sensors 602 assigned to eachgroup include at least a threshold number of sensors 602, such as atleast three sensors 602. If a subset 1002 of sensors 602 includes anumber of sensors 602 that do not satisfy the threshold number ofsensors 602 (e.g., by being less than the threshold, less than or equalto the threshold, etc.), then the logic may not utilize the datagenerated by that subset 1002 of sensors 602 by refraining from sendingthe touch sensor data generated by the sensors 602 in thebelow-threshold subset 1002 to an application (e.g., a video game) thatis configured to receive touch sensor data as input. In other words,data generated by the below-threshold subset 1002 of sensors 602 can bedisregarded or ignored for purposes of generating image data associatedwith a virtual hand (e.g., hand gestures). Additionally, oralternatively, another rule may specify that the sensors 602 assigned toeach group are to be contiguous with, or adjacent to, at least one othersensor in the group. In this manner, if a subset 1002 sensors 602includes a non-adjacent sensor that is not adjacent to any other sensor602 in the subset 1002, then the logic may not utilize the datagenerated by that non-adjacent sensor and/or the entire subset 1002 ofsensors 602 that includes the non-adjacent sensor.

In some embodiments, the logic may select the N-best sensors 602 (e.g.,capacitive pads 602) from each group, and may utilize the touch sensordata generated by the N-best sensors 602 while not utilizing the touchsensor data generated by the remaining sensors that are not included inthe selected N-best sensors. For example, in the example controllerconfiguration 1000 of FIG. 10, both the shaded-in and the unshadedsensors 602 within the bracket 1002(1) may have been assigned to a firstgroup that corresponds to a first finger of a hand, and the logic mayhave selected the “shaded-in” sensors 602 within the bracket 1002(1) asthe N-best sensors 602 that are to be utilized for finger tracking,while the unshaded sensors 602 may not be utilized. In one example,because the cluster analysis algorithm outputs cluster centers 910(1),910(2), and 910(3) that represent points in d-dimensional space thatcorrespond to the “most middle finger point,” the “most ring fingerpoint,” and the “most pinky finger point,” respectively, a predeterminednumber of the sensors 602 assigned to the “middle finger” group may beselected as the “most representative middle finger pads,” based on thedistance between those selected sensors' feature vectors and the clustercenters 910 of their corresponding clusters 906. This may be done forthe other groups as well (e.g., by selecting a predetermined number ofthe “most representative ring finger pads,” a predetermined number ofthe “most representative pinky finger pads,” etc.), and not utilizing(or disregarding/ignoring data generated by) the remaining pads 602 thatare loosely associated with two or more fingers. For example, the logicmay utilize three sensors 602 that are described by d-dimensionalfeature vectors that are closest to the converged cluster center 910(1)of the first cluster 906(1), and may ignore data from (i.e., notutilize) the remaining sensors 602 assigned to a first group associatedwith the first cluster 906(1). Additionally, or alternatively, insteadof selecting the N-best sensors 602 as those with feature vectors thatare closest to the converged cluster center 910, the N-best sensors 602may be chosen as the sensors 602 that are least likely to detectspurious input from an adjacent finger. For instance, the logic mayselect a predetermined number of sensors 602 in the “middle finger”group that are described by feature vectors farthest away from theconverged cluster center 910 of a cluster 906 associated with anadjacent finger group (e.g., the “ring finger” group). That is, thelogic may select sensors 602 (e.g., capacitive pads 602) to utilize fortracking the middle finger that are farthest away from the pads 602 thathave been assigned to the ring finger, which may avoid spurious input tothe middle finger sensors 602.

In some embodiments, the clustering algorithm can be re-run fordifferent number of k clusters. For example, if the clustering algorithmis initialized with k=4 clusters on a first pass, and if there is someindicator that k=4 is suboptimal (e.g., if there is no convergence, ifthere are too many (e.g., an above-threshold number of) pads 602assigned to the non-finger group with k=4, etc.), the clusteringalgorithm can, on a subsequent pass, be initialized with a differentvalue of k, such as k=3, and the clustering algorithm can be re-run.This may be beneficial for users who have lost a finger, and/or userswho like to use the handheld controller 100 with some, but not all, oftheir fingers.

FIGS. 11-14 illustrate various processes as a collection of blocks in alogical flow graph, which represent a sequence of operations that can beimplemented in hardware, software, or a combination thereof. In thecontext of software, the blocks represent computer executableinstructions that, when executed by one or more processors, perform therecited operations. Generally, computer-executable instructions includeroutines, programs, objects, components, data structures, and the likethat perform particular functions or implement particular abstract datatypes. The order in which the operations are described is not intendedto be construed as a limitation, and any number of the described blockscan be combined in any order and/or in parallel to implement theprocesses.

FIG. 11 is a flow diagram of an example process 1100 for calibrating andconfiguring a touch sensor 600 for different controller configurations.At 1102, logic of a controller 100 (or a system including the controller100) may receive touch sensor data from the touch sensor 600. Forinstance, an object (e.g., finger, thumb, etc.) may contact thecontroller 100 or come within a proximity of the controller 100 (e.g.,above the handle 112). The touch sensor data may indicate a capacitancevalue detected or measured by the capacitive pads 602 of the touchsensor 600. For instance, if the finger is touching the controller 100,the capacitance value may be larger than compared to a finger thathovers above the controller 100 without touching the controller 100. Inthis sense, the capacitance value may indicate a proximity of thefingers relative to the controller 100. The logic of the controller 100may convert the capacitance value into a digitized value.

In some instances, the touch sensor data received at 1102 may representraw data that is not calibrated and/or normalized with other the touchsensor data provided from other capacitive pads 602. That is, the touchdata received at 1102 may represent raw data in the sense that for aparticular capacitive pad 602, the capacitive pad 602 may detectcapacitance values or a range of capacitance values depending on thesize of the capacitive pad 602 and the size of the finger(s) and/or handof the user touching the controller 100.

At 1104, logic of the controller 100 may normalize the touch sensordata. For instance, through iteratively receiving touch sensor data fromthe touch sensor 600 (e.g., as a user interacts with the controller100), the touch sensor data may indicate capacitance values measured bythe capacitive pads 602. Over time, the capacitance values may indicatea range of capacitance values detected or measured by the individualcapacitive pads 602 of the touch sensor 600. For instance, thecapacitive pads 602 may detect a high capacitance value when the usergrips a portion of the controller 100 residing above the capacitive pad602, and may detect a low capacitance value when the user does not gripthe portion of the controller 100 residing above the capacitive pad 602.Accordingly, at 1104, for respective capacitive pads 602 of the touchsensor 600, logic of the controller 100 may analyze the touch sensordata and determine the range of capacitance values received, the maximumcapacitance value received, the minimum capacitance value received, theaverage capacitance value, and/or the median capacitance value. In someinstances, the capacitance value may be normalized in a range of [0,1].

At 1106, logic of the controller 100 may calibrate the touch sensor 600.As shown by the sub-blocks in FIG. 11, the process 1100 may involve moredetailed operations for calibrating the touch sensor 600. For example,calibrating the touch sensor 600 may include sub-blocks 1108 and 1110.As shown by sub-block 1108, calibrating the touch sensor 600 may includea discrete gesture recognition. The discrete gesture recognition maycorrespond to a discrete gesture performed by the user at the controller100. For instance, if all or a majority of the capacitance values of thecapacitive pads 602 suddenly drop, the logic may associate this dropwith the user releasing his or her hand from the controller 100 orreleasing a particular finger from the controller 100. The capacitancevalues received as the user suddenly releases his or her finger from thecontroller 100 may correspond to a low-level value of a range ofcapacitance values detected for a particular capacitive pad 602 (e.g.,the capacitance value represents when the finger is not touching thecontroller 100). The capacitance values received prior to the suddendrop may correspond to a high-level value of the range of capacitancevalues detected for the particular capacitive pad 602 (e.g., thecapacitance value represents when the finger is touch the controller100). With the range of capacitance values, the logic of controller 100may calculate a bias and a scale factor for capacitance values receivedby the controller 100. That is, knowing the scale factor for acapacitive pad 602 allows for the normalization of capacitance valuesreceived.

As shown by sub-block 1110, calibrating the touch sensor 600 may alsoinclude a continuous low-level and/or high-level adjustment. As thelogic of the controller 100 continuously receives touch sensor data fromthe touch sensor 600, the logic may continuously monitor the touchsensor data to re-calibrate the low-level capacitance value and/or thehigh-level capacitance value for the range of capacitance values of agiven capacitive pad 602. For instance, through continuously receivingthe touch sensor data from the individual capacitive pads 602, logic ofthe controller 100 may determine whether the received capacitance valuesare lower than or higher than the previously determined low-levelcapacitance value and/or the high-level capacitance value, respectively.Based on this determination, the logic of the controller 100 may updatethe low-level capacitance value or the high-level capacitance value,thereby adjusting the range of capacitance values for a particularcapacitive pad 602. In doing so, the bias and/or scale factor may beupdated for use in normalizing the capacitance values. Calibrating thetouch sensor 600 may therefore aid in calculating the bias and scalefactor for a particular capacitive pad 602 and for a particular useroperating the controller 100.

At 1112, the logic of the controller 100 may configure the touch sensor600, whereby the capacitive pads 602 are assigned to certain fingers ofthe user based on the cluster analysis, as described herein. In thisway, using the cluster-based sensor assignment approach describedherein, the controller 100 may map certain capacitive pads 602 and theircapacitance values to certain fingers of the user. As shown by thesub-blocks in FIG. 11, the process 1100 may involve more detailedoperations to configure the touch sensor 600. For example, configuringthe touch sensor 600, in addition to using a clustering algorithm, mayinvolve filtering noise at the low-level range capacitance values, atsub-block 1114, and a capacitive pad and finger rejection, at sub-block1116, each of which are discussed in turn.

At sub-block 1114, the process 1100 may filter noise within a low-levelrange of capacitance values. For instance, when a finger is not touchingthe controller 100 (e.g., hovering above the handle 112 or in closeproximity to the handle 112), those capacitive pads 602 associated withthe finger may be susceptible to noise. In other words, at the low-levelrange of capacitance values for a capacitive pad 602, a small amount ofmeasured capacitance may result in changes of the finger position of theuser. Generating image data corresponding to these changes may result inunpleasant finger twitching within a VR environment. Instead, ininstances where the capacitance values from the touch sensor 600 forindividual capacitive pads 602 fall below a certain threshold, are belowthreshold change from previous capacitance values, or if the capacitancevalues are within a certain threshold of the low-level capacitance valuefor the capacitive pad 602, the logic of the controller 100 may suppressthe capacitance value. In doing so, the controller 100 may ignore minorspurious touch inputs at the touch sensor 600 that may otherwise resultin finger twitching within the VR environment.

The capacitive pad and finger rejection, at sub-block 1116, may includeidentifying capacitive pads 602 whose low-level capacitance value orhigh-level capacitance value are within a threshold range of oneanother. For instance, if the low-level and high-level capacitancevalues are separated by a small range, the capacitive pad may be unableto accurately sense and detect the finger positions of the user insufficient detail. Here, as a capacitive pad 602 may detect capacitancevalues within a threshold range, the measured capacitance values may notaccurately correspond to the finger position.

Additionally, or alternatively, certain fingers may be associated with anumber of capacitive pads 602 that decreases the reliability of thedetected capacitance values. In these scenarios, capacitance valuesreceived by the capacitive pads 602 may introduce noise. Disregardingcertain capacitive pads 602, or groups of capacitive pads 602, mayincrease a reliability that the capacitance values correspond to thehand gesture of the user.

While the process 1100 is described being performed by the controller100, in some instances, the one or more communicatively coupledcomputing devices may perform all of or a portion of the blocks of theprocess 1100. For instance, as the one or more computing devices mayinclude increased processing, the controller 100 may transmit the touchdata received from touch sensor 600 to the computing device forcalibrating and normalizing the capacitance values.

FIG. 12 illustrates an example process 1200 for configuring a controller100 according to a controller configuration based on cluster analysis.At 1202, logic of a controller 100 (or a system including the controller100) may receive data generated by the sensors 602 of the touch sensor600. For instance, an object (e.g., finger, thumb, etc.) may contact thecontroller 100 or come within a proximity of the controller 100 (e.g.,above the handle 112), and the touch sensor 600 may generate data (e.g.,capacitance values).

At 1204, based at least in part on the touch sensor data received atblock 1202, a covariance matrix 800 may be generated that indicatescorrelations between pairs of sensors 602 of the plurality of sensors.For example, the covariance matrix 800 may be generated based on asubset of d reference sensors, such as the “shaded-in” sensors shown inFIG. 7, to generate a n×d covariance matrix 800 for a set of n sensors.In some cases, n is a first integer, d is a second integer, and thesecond integer, d, is less than the first integer, n. By choosing asubset of d reference sensors in this manner, computing resources areconserved and computation is more efficient because not all possiblepairs of sensors are evaluated for a positive correlation therebetween.In some embodiments, the subset of d reference sensors used to generatethe covariance matrix 800 comprises a column of sensors 602, such as thecolumn of “shaded-in” sensors shown in FIG. 7. As shown by thesub-blocks in FIG. 12, the process 1200 may involve more detailedoperations for generating the covariance matrix 800. For example,generating the covariance matrix 800 may include sub-blocks 1203, 1205,1207, and 1209.

At sub-block 1203, statistics may be calculated based at least in parton the touch sensor data received over the period of time. For example,average capacitance values over the last p samples can be calculatedwith respect to individual sensors 602 (e.g., capacitive pads).

At sub-block 1205, the subset of d reference sensors 602 may be selectedfrom among the plurality of sensors 602. It is to be appreciated that,in some embodiments, the reference sensors are predetermined, but atsub-block 1205, these reference sensors may be dynamically determined.In some embodiments, this may be based on the user such that differentreference sensors are selected for different users.

At sub-block 1207, covariance values between pairs of sensors may bedetermined based at least in part on the statistics calculated atsub-block 1203. For instance, average capacitance values between pairsof sensors 602 may be compared, and based on a difference between thecompared capacitance values, a covariance value may be determined. Insome embodiments, these covariance values are determined as values thatrange from negative one to positive one [−1,+1], or from zero to one[0,+1]. At sub-block 1209, the covariance matrix 800 may be populatedwith the covariance values determined at sub-block 1207.

At 1206, based at least in part on the covariance matrix 800, aplurality of d-dimensional feature vectors are determined. Each featurevector may correspond to a sensor 602 of the plurality of n sensors.Each feature vector may also describe correlations between the sensor602 and the subset of d reference sensors 602 of the plurality of nsensors.

At 1208, a clustering algorithm may be used to cluster the plurality ofd-dimensional feature vectors. For example, a k-means clusteringalgorithm can be used at block 1208. As shown by the sub-blocks in FIG.12, the process 1200 may involve more detailed operations for clusteringthe feature vectors. For example, clustering of the feature vectors mayinclude sub-blocks 1211, 1213, and 1215.

At sub-block 1211, a clustering algorithm, such as a k-means clusteringalgorithm, may be initialized with input parameters. These inputparameters may include, without limitation, a number of k clusters 906(e.g., k=4), and center estimates 908 for the k clusters 906 ind-dimensional space.

At sub-block 1213, each feature vector of the plurality of featurevectors may be assigned to a cluster 906 of the k clusters that has acenter estimate 908 that is a smallest distance from the feature vector.For example, a given feature vector is assigned to a cluster 906 havinga center estimate 908 closest to the feature vector, among the k centerestimates 908.

At sub-block 1215, each center estimate 908 is updated to obtain kupdated cluster centers 910. A center estimate 908 for a cluster 906 isupdated based at least in part on the feature vectors assigned thecluster 906. Mathematically, this update step may involve calculatingupdated means (updated cluster centers 910) of the feature vectorsassigned to the cluster 906, and updating the center estimates 908 tothose updated cluster centers 910. Sub-blocks 1213 and 1215 may iterateuntil convergence (e.g., until the updated cluster centers 910 convergeto final cluster centers).

At 1210, the touch sensor array 600 of the handheld controller 100 maybe configured according to a controller configuration 1000 based atleast in part on the clustering of the feature vectors. This configuringoperation at block 1210 may result in a controller configuration 1000that assigns at least a first subset 1002(1) of the plurality of sensors602 to a first group that corresponds to a first finger of a hand (e.g.,a middle finger), and a second subset 1002(2) of the plurality ofsensors 602 to a second group that corresponds to a second finger of thehand (e.g., a ring finger). For k=2, these may be the two groups ofassigned sensors. For k=3, the controller configuration 1000 may assigna third subset 1002(3) of the plurality of sensors 602 to a third groupthat corresponds to a third finger of the hand (e.g., a pinky finger).For k=4, he controller configuration 1000 may assign a fourth subset1002 of the plurality of sensors 602 to a fourth group that correspondsto a non-finger group for untouched, or seldom touched, sensors 602, ora fourth group that corresponds to a fourth finger (e.g., the indexfinger). While the process 1200 is described being performed by thecontroller 100, in some instances, the one or more communicativelycoupled computing devices may perform all of or a portion of the blocksof the process 1200.

FIG. 13 is a flow diagram of an example process 1300 for selectingcertain sensors 602 to utilize after the touch sensor array 600 has beenconfigured according to a controller configuration 1000. In someinstances, the process 1300 may continue from “A” of process 1200. At1302, logic of the controller 100 (or of a system including thecontroller 100) may determine if a criterion (or criteria) is/are metbased at least in part on the controller configuration 1000 of the touchsensor array 600. For example, at 1302, the logic may determine whetherany of the subsets 1002 of sensors 602 assigned to a particular group(e.g., a finger group) includes a number of sensors 602 that do notsatisfy a threshold number of sensors 602. The threshold may besatisfied if the number of sensors 602 assigned to a particular groupmeet or exceed the threshold, or if the number of sensors 602 strictlyexceeds the threshold. For example, a criterion may be met if eachsubset includes at least three sensors 602. As another example, at 1302,the logic may determine whether any of the subsets 1002 of sensors 602assigned to a particular group (e.g., a finger group) includes anon-adjacent sensor that is not adjacent to any other sensor assigned tothat particular group (i.e., an isolated sensor within that group).Thus, this example criterion may be met if each sensor 602 in eachsubset is contiguous with, or adjacent to, at least one other sensor 602in the group to which that sensor 602 is assigned.

If the criterion (or criteria) is/are not met, the process 1300 mayfollow the “NO” route from block 1302 to block 1304. For example, if thelogic determines that a criterion is not met because at least one subset1002 of sensors 602 assigned to a group includes a number of sensorsthat do not satisfy a threshold number of sensors, the logic, at block1304, may refrain from utilizing the data generated by the sensors inthat subset, such as by refraining from sending data generated by thesubset of sensors 602 to an application (e.g., a video game) configuredto receive touch sensor data as input. As another example, if the logicdetermines that a criterion is not met because at least one subset 1002of sensors 602 assigned to a group includes a non-adjacent sensor thatis not adjacent to any other sensor 602 in that subset, the logic, atblock 1304, may refrain from utilizing data generated by thatnon-adjacent sensor and/or data generated by the subset of sensors thatare assigned to the same group as the non-adjacent sensor. Again,refraining from utilizing the touch sensor data may include refrainingfrom sending the touch sensor data to an application (e.g., a videogame) configured to receive touch sensor data as input.

After designating one or more sensors 602, or subsets 1002 of sensors602, as sensors to ignore at block 1304, or following the “YES” routefrom block 1302 if the criterion (or criteria) is met, the process 1300may proceed to block 1306. At 1306, the logic may select the N-best(e.g., a predetermined number of) sensors 602 from individual subsets1002 of sensors assigned to respective groups, the N-best sensors 602being those whose touch sensor data is to be utilized (e.g., thosesensors 602 that are to be utilized with an application configured toreceive data generated by the touch sensor array 600 as input). Ways ofselecting the N-best sensors are described herein, such as the N-bestsensors with feature vectors closest (in distance) to the cluster center910 of the corresponding cluster 906 to which those feature vectors areassigned, selecting the N-best sensors with feature vectors farthest (indistance) from a cluster center 910 of an adjacent group (e.g.,selecting a predetermined number of middle finger sensors that aredescribed by feature vectors that are farthest from a cluster center 910of the ring finger cluster 906).

At 1308, with the controller configuration set and the N-best sensorsselected in each subset, logic of the controller 100 (or of a systemincluding the controller 100) may normalize the capacitance values ofthe utilized sensors 602 using a set of weights applied to theindividual capacitive pads 602 of a group of capacitive pads 602associated with a finger. For instance, the weight assigned toindividual pads of the capacitive pads 602 may be associated with thecontroller configuration. For instance, if four capacitive pads 602 ofthe touch sensor 600 are associated with the middle finger of a user, anequal weight may be assigned to all four capacitive pads 602. Therefore,the capacitance values received from these four capacitive pads 602 mayinclude a weight of one-quarter. In doing so, the capacitance valuesfrom these capacitive pads 602 may include an equal weight that is usedwhen determining a finger position. Additionally, in some instances, theweight of a particular capacitive pad 602 may be set to zero based onthe capacitive pad and finger rejection indicating which capacitive pads602 to ignore or have a reliability below a certain threshold.

Normalizing the touch sensor data at 1308 may also involve summing thecapacitance values from the capacitive pads 602 for each group ofcapacitive pads 602. As an example, for a certain controllerconfiguration, if the middle finger is represented by four capacitivepads 602, each capacitance value of the capacitive pad 602 of the middlefinger may carry a weight of one-fourth. The logic may weigh thecapacitance value for respective capacitive pads 602 for a finger toindicate the influence that the capacitance value for a given capacitivepad 602 has on the summed capacitance values for the finger.

Additionally, or alternatively, normalizing the touch sensor data mayinclude normalizing the touch sensor data according to weightspreviously applied to the capacitive pads 602. Through the capacitivepad and finger rejection (sub-block 1116), not all capacitive pads 602within a group of capacitive pads 602 may carry an equal weight. As anexample, a user might not contact certain capacitive pads 602 with agroup. In turn, the logic may reject or not factor the capacitance valueof a particular capacitive pad 602 the user does not touch, forinstance, if the hand of the user is small or the user places his or herhands differently on the controller 100. For instance, as noted above,if the low-level capacitance value and high-level capacitance value arenarrow (i.e., the range is small), the capacitive pad 602 may besusceptible to high amounts of noise. Here, the logic of the controller100 may disregard certain capacitance values of a capacitive pad 602within the weighted sum. In instances were capacitance values are notused, the capacitance values being used may be summed and divided by thesum of the weights being used. For instance, if four capacitive pads 602are assigned to a particular finger, each capacitive pad 602 may have aweight of one-quarter. However, if the capacitance value for one of thecapacitive pads 602 is unreliable (e.g., contains a large amount ofnoise) the weight of the one capacitive pad 602 may be disregarded suchthat the remaining three capacitive pads have a weight of one-third.Therein, the capacitive values are summed and divided by the sum of theweights of the capacitive pads 602 being used.

At 1310, the logic of the controller 100 may assign a finger value torespective fingers of the user based at least in part on the touchsensor data. For instance, after normalizing the touch sensor data andassociating the touch sensor data with particular fingers, thecontroller 100 may determine a finger value on a scale of [0,1]. Thefinger value assigned to fingers of the user may indicate a relativeposition or curl of the finger relative to the controller 100. In thissense, the controller 100, using the capacitance values detected fromindividual capacitive pads, may determine the finger positions of theuser relative to the controller 100. In some instances, the controller100 may determine finger values for each finger of the user or thosefingers for which the touch sensor 600 is configured.

At 1312, the logic of the controller 100 may transmit the finger values(e.g., indication) to one or more computing devices and/or anapplication configured to receive touch sensor data as input. In someinstances, the one or more computing devices may utilize the fingervalues to generate image data depicting a gesture of the hand of theuser on the controller 100. In some embodiments, the one or morecomputing devices may perform additional analysis on the finger value.For instance, the one or more computing devices may utilize curl logicwhen generating a curl of the finger in the image data. Moreover, insome instances, the controller 100 may transmit additional data capturedand/or received by the controller 100, such as force data from apressure sensor of the controller 100 upon a press of the surface by theat least one finger.

From 1312, the process 1300 may loop to step 1202 of the process 1200.Accordingly, the controller 100 may continuously receive capacitancevalues for use in generating image data according to the grip of theuser and for use in dynamically determining/updating the controllerconfiguration of the controller 100 based on cluster analysis, asdescribed herein.

While some or all of the process 1300 is described being performed bythe controller 100, in some instances, the one or more communicativelycoupled computing device may perform all of or a portion of the blocksof the process 1300. For instance, as the computing device may includeincreased processing power, the controller may transmit the touch datareceived from touch sensor 600 to the computing device for determiningthe cluster-based sensor assignment that is used for determining thecontroller configuration 1000. In turn, the computing device maytransmit the controller configuration 1000 to the controller 100, ortransmit an indication of the controller configuration 1000 to thecontroller 100.

FIG. 14 illustrates a process 1400 for calibrating a touch sensor of acontroller, such as the touch sensor 600 of the controller 100, reducingnoise within the touch sensor data, and utilizing the touch sensor datato generate image data representative of hand gestures performed by theuser. In some instances, the process 1400 may output a finger value orindication representative of a position of the finger, such as how mucha finger curls or extends.

At 1402, the process 1400 may receive touch sensor data from the touchsensor 600, where the touch sensor data represents or indicates rawcapacitance values detected by capacitive pads (e.g., the capacitivepads 602) of the touch sensor 600. In some instances, the process 1400may receive capacitance values from individual capacitive pads 602, asillustrated by a₁, a_(i), and a_(N). In some instances, the process 1400may receive the raw capacitive values from the touch sensor 600 for eachframe displayed in a VR environment.

At 1404, the process 1400 may perform a factory normalization tonormalize the raw capacitance values. For instance, the capacitive pads602 may have different biases, scale factors, and offsets depending onmanufacturing conditions, a size of the capacitive pad 602, and soforth. In some instances, the factory normalization may involve a firstorder calibration to remove the bias within the capacitance value andnormalizing the capacitance value.

At 1406, the process 1400 may perform a grip calibration. As shown, thegrip calibration may involve sub-blocks 1408, 1410, and 1412, which arediscussed in detail in turn.

At sub-block 1408, the process 1400 may perform a statistical analysisto observe a range of capacitance values, the maximum capacitance valuereceived, the minimum capacitance value received, the averagecapacitance value, and/or the median capacitance value for respectivecapacitive pads 602.

At 1410, the process 1400 may perform a discrete gesture detection.Here, the process 1400 may analyze the touch sensor data (i.e., thecapacitance values), after being normalized according to the factorynormalization, to detect a discrete gesture at the controller 100. Forinstance, if the touch sensor data indicates that capacitance values ofthe capacitive pads 602, or a portion thereof, suddenly drop, theprocess 1400 may associate this drop of capacitance values with the userreleasing his or her hand from the controller 100 or releasing aparticular finger from the controller 100. The capacitance valuesreceived as the user suddenly releases his or her finger from thecontroller 100 may correspond to a low-level value for a range ofcapacitance values detected by a particular capacitive pad 602 (e.g.,where the capacitance value represents when the finger is not touchingthe controller 100). The capacitance values received prior to the suddendrop may correspond to a high-level value of the range of capacitancevalues detected by a particular capacitive pad 602 (e.g., where thecapacitance value represents when the finger is touching the controller100). With the range of capacitance values, the process 1400 maydetermine a bias and a scale factor for capacitance values of thecapacitive pads 602 to normalize the capacitance values received atrespective capacitive pads 602.

At 1412, the process 1400 may perform a continuous calibration updateand decay. As the process 1400 may continuously receive touch sensordata from the touch sensor 600, the process 1400 may continuouslymonitor the touch sensor data to re-calibrate or reset the low-levelcapacitance value and/or the high-level capacitance value for the rangeof capacitance values for a given capacitive pad 602. In other words,through continuously receiving the touch sensor data from the individualcapacitive pads 602, the process 1400 may determine whether thecapacitance values are lower than or higher than the previouslydetermined low-level capacitance value of the range and/or thehigh-level capacitance value of the range, respectively. For instance,as the capacitance changes through a gameplay experience (e.g., handsbecome sweaty or dry, humidity, temperature, etc.), the process 1400 maydetermine, or set, a new low-level capacitance value or a new high-levelcapacitance value, thereby adjusting the range of capacitance valuesdetected by a capacitive pad 602. Additionally, in some instances, thecontinuous calibration may reduce a dependence on the process 1400determining the discrete gesture detection at 1410.

In some instances, the process 1400 may assign a weight or percentage toa newly detected low-level capacitance value or a newly detectedhigh-level capacitance value to update the low-level capacitance valueor high-level capacitance value, respectively. For instance, if theprocess 1400 detects a capacitance value below a previously detectedlow-level capacitance value for a certain amount of time, the process1400 may weigh the capacitance value to update the low-level capacitancevalue.

Additionally, the low-level capacitance value or high-level capacitancevalue may decay over time depending on how the user grips the controller100, environmental conditions (e.g., humidity), or other properties(e.g., skin wetness). The amount the low-level capacitance value and thehigh-level capacitance value may decay may be limited, such that thelow-level capacitance value and the high-level capacitance value areseparated by a threshold amount of range to reduce sensor noise. In someinstances, the decay may depend on time and/or a rate of change in thecapacitance values. For instance, if the user taps their fingers on thecontroller 100, or the controller 100 switches users, therebypotentially causing a change in the capacitance values received, therate of decay may increase to reduce an amount of time required toupdate the low-level and/or the high-level capacitance values.

As a result of the grip calibration at 1406, and the sub-blocks1408-1412, the capacitive values sensed from each capacitive pad 602 maybe normalized on a scale of [0,1]. The scale of [0,1] may represent, fora particular grip of a user and for the individual capacitive pads 602,the high and low levels for the capacitance values sensed from the touchsensor 600.

At 1414, the process 1400 may perform a weighted sum of the capacitivevalues. As the capacitive values are normalized on the scale of [0,1],the process 1400 may assign a weight to capacitance values from thecapacitive pads 602 depending on the controller configuration. That is,the capacitance values are normalized between [0,1] and weights areassigned to individual capacitance values received the individualcapacitive pads 602. For instance, if a certain controller configurationincludes five capacitive pads 602 assigned to a particular finger, thecapacitance values may include an equal weight (e.g., one-fifth). Inother words, when the capacitive pads 602 detect a maximum capacitancevalue, the output of the weighted sum may equal one.

As shown, determining the weighted sum may involve sub-blocks 1418,1420, and 1422. At sub-block 1418, the process 1400 may perform adynamic controller configuration determination that is based on clusteranalysis, as described herein. For example, the process 1400 maygenerate a covariance matrix 800 from touch sensor data (e.g.,capacitance values) in order to derive feature vectors that areclustered into groups. Based on this clustering, sensors 602 may beassigned to groups that may correspond to fingers of a hand, such as byassigning a first subset of sensors 602 to a first group correspondingto a first finger, a second subset of sensors 602 to a second groupcorresponding to a second finger, and so on for any suitable number ofgroups/clusters.

At sub-block 1420, the process 1400 may filter noise contained withinthe capacitance values. For instance, when a finger is not touching thecontroller 100, such as when a finger is fully extended, thosecapacitive pads 602 associated with the finger not touching thecontroller 100 may be susceptible to noise. Here, detecting a smallamount of capacitance may cause a large amount of noise within thereceived capacitance value. In instances where the capacitance valuesfrom the touch sensor 600 for individual capacitive pads 602 fall belowa certain threshold, or if the capacitance values are within a certainlimit of the low-level capacitance value for the capacitive pads 602,the process 1400 may suppress a detected capacitance. In otherinstances, in such scenarios, the process 1400 may assign a low weightto the capacitance values.

At sub-block 1422, the process 1400 may reject certain capacitancevalues from capacitive pads 602 of the touch sensor 600 and/or fingersassociated with respective capacitive pads 602. For instance, at 1420the process 1400 may identify capacitive pads 602 that have a smallrange between the low-level capacitance value or high-level capacitancevalue. In these scenarios, capacitance values received by the capacitivepads 602 may introduce noise and disregarding certain capacitive pads602, or groups of capacitive pads 602, may increase a reliability thatthe touch sensor data corresponds to the hand gesture of the user. Thatis, if the range of capacitance values detected by a capacitive pad 602is small, the capacitive pad 602 may be susceptible to large amounts ofnoise.

Additionally, or alternatively, certain fingers may be associated with anumber of capacitive pads 602 having a low reliability. Rejectingcertain fingers, or a group of capacitive pads 602, introduces acontingency behavior for controller configurations for small hand. Inthese scenarios, a respective finger may associate with adjacent fingers(e.g., pinky finger associates with ring finger). Additionally, oralternatively, as described with respect to FIG. 13, the process 1400may reject certain touch sensor data if a criterion (or criteria) is notmet, such as a subset of sensors 602 assigned to a finger group that hasa below-threshold number of sensors assigned to that group (e.g., 2 orfewer sensors assigned to the finger group), and/or a subset of sensors602 assigned to a finger group that has a non-adjacent (or isolated)sensor that is not contiguous (on the touch sensor array 600) with anyother sensors in its assigned group. Additionally, or alternatively, thepad rejection at block 1422 may involve selecting the N-best sensors602, as described herein, and rejecting touch sensor data from remainingsensors that are not included in the N-best sensors 602.

At 1424, the process 1400 may perform a final normalization. Forexample, in some instances, a capacitive pad 602 assigned to aparticular finger may not detect a capacitance value or the capacitancevalues may be unreliable. Here, the user may not touch certaincapacitive pads 602 of the touch sensor 600 because of the size of thehand or in instances where the user readjusted his or her grip.Additionally, in some instances where the low-level and high-levelcapacitance values are narrow, or separated by a small range, thecapacitance values may be unreliable and noise may significantly impactfinger motion. To eliminate or decrease noise from these capacitivepad(s) 602, the final normalization 1424 may determine a reliability ofthe capacitance values, and if a reliability is low, the weight of acapacitive value from a capacitive pad 602 is removed from the weightedsum. Therein, the capacitive values are summed and divided by the sum ofthe weights of the capacitive pads 602 being used.

At 1426, the process 1400 may filter and curve fit the touch sensor datato represent a hand gesture of the user. The filtering and curve fittingmay involve linearizing the final normalization of the touch data on the[0,1] scale to achieve a linear relationship between the touch sensordata and a position of a finger (e.g., curled, extended, half-wayextended, etc.). For instance, the final normalization values determinedat 1424 may follow an exponential curve, such that as the hand of theuser comes into proximity of the controller 100, or grips the controller100, the final normalized values exponentially increase. In other words,the summed capacitance value may be exponentially related to theproximity with the finger disposed on/around the controller 100.Linearizing the values on a [0,1] scale such that the capacitance valuesare correlated with a finger position may reduce sensitivity and animpact that noise may have when a finger is extended from the controller100, as well as when a finger touches or is in close proximity to thecontroller 100.

As shown, the filtering and curve fitting may involve various sub-blocksto achieve final values that are utilized to generate hand gestures. Atthe filtering and curve fit stage 1426, the process 1400 may applyfiltering before or after the curve fit. For instance, the sub-blocksmay involve filtering capacitance values within the low-level range ofcapacitance values when the capacitive pads 602 are susceptible tonoise. In other words, within the high-level capacitance range, such aswhen the fingers grip the controller 100 or are in close proximity tothe controller 100, the capacitive pads 602 are less susceptible tonoise.

The process 1400 may apply adaptive filtering at 1428 to adjust theamount of filtering performed on the capacitance values. The adaptivefiltering may adaptively filter to more aggressively filter thecapacitance values within the low-range of capacitance values comparedto the capacitance values are within the high range of capacitancevalues. As shown, the adaptive filtering may involve sub-blocks 1430,1432, and 1434. In general, the adaptive filtering at 1426 may utilizethe results of sub-blocks 1430, 1432, and 1434 to determine how muchnoise exists in the normalized value to determine an amount of filteringto be applied to the normalized capacitance values. Determining anamount of noise that exists in the capacitance values may involvedetermining which capacitive pads 602 are being used to generate thecapacitance values, as well as the high-level and low-level capacitancevalues for the respective capacitive pads 602. For instance, thecapacitive pads 602 may have a baseline noise and if the range betweenthe high-level and low-level capacitance values for a capacitive pad 602is low, the baseline noise of the capacitive pad 602 may equate to alarge amount of finger movement (i.e., baseline noise is a largefraction of the range of capacitance values the capacitive pad 602 isable to sense). Here, the signal to noise ratio may be high.Comparatively, if the range between the high-level and low-levelcapacitance values for a capacitive pad 602 is large, then the baselinenoise of the capacitive pad 602 may not introduce a large amount offinger movement. In these scenarios, to reduce the noise within thecapacitance values, when the range of capacitance values is small, theprocess 1400 may filter capacitance values more heavily than when therange of capacitance values is larger. The filtering and curve fit 1426may be repeated for each capacitive pad 602 as each capacitive pad 602may include respective high and low level capacitance values.Additionally, the amount of filtering applied at 1426 may depend onwhich capacitive pads 602 and/or which capacitive pads 602 have beenrejected (e.g., pad and finger rejection 1422).

The sum noise prediction at 1430 may filter the capacitance values basedon which capacitive pads 602 are being used, the weights assigned thecapacitive pads 602, as well as the respective baseline noise for thecapacitive pads 602. For instance, the process 1400 may include adefault capacitive pad noise at 1428, which may represent an estimatedbaseline noise for individual capacitive pads 602. The sum noiseprediction step at 1430 may therefore determine, for those capacitivepads 602 being used, their respective baseline noise values. The sumnoise prediction step may also determine the expected or predicted noisefor the capacitive pads 602. For instance, if the capacitive pads 602being used sense capacitive values over a large range (i.e., between thelow level and high level capacitance values), the capacitance values mayinclude a low amount of noise and less filtering may be applied.However, if the range of capacitance values for a capacitive pad 602 isnarrow (i.e., between the low level and high level capacitance values),then the capacitance values may include a large amount of noise and theprocess 1400 may apply a greater amount of filtering.

The dNorm/dt at 1432 may take into consideration a change in capacitancevalue over time. For instance, if the received capacitance values from acapacitive pad 602 change significantly over a short period of time(e.g., one frame), the potential noise introduced within the capacitancevalues may be disregarded or weighted accordingly. That is, instead offiltering the capacitive values and introducing latency, if thecapacitance values change over a threshold amount over a thresholdamount of time, less filtering may be applied to the capacitive values.In this sense, less filtering may be applied when greater fingermovement is detected and more filtering may be applied when less fingermovement is detected.

The dCurl/dNorm at 1434 may filter the normalized capacitance valuebased on an amount of capacitance detected. For instance, in thehigh-range of capacitance values, where the finger grips the controller,less filtering may be applied because the noise may have less of animpact on finger position. However, at the low range of capacitancevalues, where the finger is displaced from the controller, or in closeproximity, more filtering may be applied because small changes incapacitance values may have a significant impact on the position of thefinger. Here, a small change in capacitance values may result in a largechange of the finger gesture.

At sub-block 1438, the lo-pass filter may represent a tunable lo-passmean filter that adjusts the amount of filtering on detected capacitancevalues. In some instances, the amount of filtering may be on a scale of[0,1] and may be based on the result of the amount of filteringdetermined at the adaptive filter 1428. That is, the lo-pass filter mayfilter the capacitance values as determined from the adaptive filtering.

At sub-block 1440, the process 1400 may curve fit the capacitance valueson a [0,1] scale to associate the capacitance values with a position ofthe finger, or a hand animation. For each finger, the output of thecurve fit may include a number for each finger, where the numberindicates the finger position of each finger of the hand.

At sub-block 1442, the process 1400 may apply a backlash filter afterthe curve to filter changes in capacitance values that fall below athreshold. For instance, if the capacitance values do not change by athreshold amount on the [0,1] scale, the capacitance values may befiltered. Such filtering may reduce perceived finger twitching andmotion by the user.

At sub-block 1444, the joint model may correspond to a hand animation(e.g., a hand skeleton). For instance, the joint model may generate ahand animation corresponding to the number assigned to individualfingers of the hand from the curve fit at 1440.

FIG. 15 illustrates example components of a controller 1500, such as thecontroller 100. In some embodiments, the example components shown inFIG. 15 may be implemented on any computing device that is part of asystem including the controller 1500, such as by implementing one ormore of the components on a game console or personal computer that iscommunicatively coupled to the controller 1500. As illustrated, thecontroller 1500 includes one or more input/output (I/O) devices 1502,such as the controls described above (e.g., joysticks, trackpads,triggers, etc.), and/or potentially any other type of input or outputdevices. For example, the I/O devices 1502 may include one or moremicrophones to receive audio input, such as user voice input. In someimplementations, one or more cameras or other types of sensors (e.g.,inertial measurement unit (IMU)) may function as input devices toreceive gestural input, such as motion of the controller 1500. In someembodiments, additional input devices may be provided in the form of akeyboard, keypad, mouse, touch screen, joystick, control buttons and thelike. The input device(s) may further include control mechanisms, suchas basic volume control button(s) for increasing/decreasing volume, aswell as power and reset buttons. The output devices, meanwhile, mayinclude a display, a light element (e.g., LED), a vibrator to createhaptic sensations, a speaker(s) (e.g., headphones), and/or the like.There may also be a simple light element (e.g., LED) to indicate a statesuch as, for example, when the controller 1500 is powered on. While afew examples have been provided, the controller 1500 may additionally oralternatively comprise any other type of output device.

In some instances, output by the one or more output devices may be basedon input received by one or more of the input devices. For example,selection of a control touch input at the controller 1500 may result inthe output of a haptic response by a vibrator located adjacent (e.g.,underneath) the control and/or at any other location. In some instances,the output may vary based at least in part on a characteristic of thetouch input on a touch sensor 600, such as the capacitive pads 602disposed on/within the handle 112 of the controller 100. For example, atouch input at a first location on the handle 112 may result in a firsthaptic output, while a touch input at a second location on the handle112 may result in a second haptic output. Furthermore, a particulargesture on the handle 112 may result in a particular haptic output (orother type of output). For instance, a tap and hold gesture (detected bythe touch sensor 600) on the handle 112 may result in a first type ofhaptic output, while a tap and release gesture on the handle 112 mayresult in a second type of haptic output, while a hard tap of the handle112 may result in a third type of haptic output.

In addition, the controller 1500 may include one or more communicationinterfaces 1504 to facilitate a wireless connection to a network and/orto one or more remote systems (e.g., a host computing device executingan application, a game console, other controllers, etc.). Thecommunication interfaces 1504 may implement one or more of variouswireless technologies, such as Wi-Fi, Bluetooth, radio frequency (RF),and so on. Additionally, or alternatively, the controller 1500 mayinclude physical ports to facilitate a wired connection to a network, aconnected peripheral device, or a plug-in network device thatcommunicates with other wireless networks.

In the illustrated implementation, the controller 1500 further includesone or more processors 1506 and computer-readable media 1508. In someimplementations, the processors(s) 1506 may include a central processingunit (CPU), a graphics processing unit (GPU), both CPU and GPU, amicroprocessor, a digital signal processor, or other known processingunits or components. Additionally, or alternatively, the functionallydescribed herein can be performed, at least in part, by one or morehardware logic components. For example, and without limitation,illustrative types of hardware logic components that can be used includefield-programmable gate arrays (FPGAs), application-specific integratedcircuits (ASICs), application-specific standard products (ASSPs),system-on-a-chip systems (SOCs), complex programmable logic devices(CPLDs), etc. Additionally, each of the processor(s) 1506 may possessits own local memory, which also may store program modules, programdata, and/or one or more operating systems.

The computer-readable media 1508 may include volatile and nonvolatilememory, removable and non-removable media implemented in any method ortechnology for storage of information, such as computer-readableinstructions, data structures, program modules, or other data. Suchmemory includes, but is not limited to, RAM, ROM, EEPROM, flash memoryor other memory technology, CD-ROM, digital versatile disks (DVD) orother optical storage, magnetic cassettes, magnetic tape, magnetic diskstorage or other magnetic storage devices, RAID storage systems, or anyother medium which can be used to store the desired information andwhich can be accessed by a computing device. The computer-readable media1508 may be implemented as computer-readable storage media (“CRSM”),which may be any available physical media accessible by the processor(s)1506 to execute instructions stored on the computer-readable media 1508.In one implementation, CRSM may include random access memory (“RAM”) andFlash memory. In other implementations, CRSM may include, but is notlimited to, read-only memory (“ROM”), electrically erasable programmableread-only memory (“EEPROM”), or any other tangible medium which can beused to store the desired information and which can be accessed by theprocessor(s) 1506.

Several modules such as instruction, datastores, and so forth may bestored within the computer-readable media 1508 and configured to executeon the processor(s) 1506. A few example functional modules are shown asstored in the computer-readable media 1508 and executed on theprocessor(s) 1506, although the same functionality may alternatively beimplemented in hardware, firmware, or as a system on a chip (SOC). Anoperating system module 1510 may be configured to manage hardware withinand coupled to the controller 1500 for the benefit of other modules. Inaddition, the computer-readable media 1508 may store anetwork-communications module 1512 that enables the controller 1500 tocommunicate, via one or more of the communication interfaces 1504, withone or more other devices, such as a personal computing device executingan application (e.g., a game application), a game console, a remoteserver, other controller(s), computing devices, or the like. Thecomputer-readable media 1508 may further include a game-session database1514 to store data associated with a game (or other application)executing on the controller 1500 or on a computing device coupled to thecontroller 1500.

The computer-readable media 1508 may also include a device recorddatabase 1516 that stores data associated with devices coupled to thecontroller 1500, such as the personal computing device, game console,remote server, or the like. The computer-readable media 1508 may furtherstore game-control instructions 1518 that configure the controller 1500to function as a gaming controller, and universal-control instructions1520 that configure the controller 1500 to function as a controller ofother, non-gaming devices. The computer-readable media 1508 mayadditionally store controller configuration(s) 1522. The controllerconfiguration(s) 1522 may represent or include data associated with thedynamic assignment of the capacitive pads 602 of the touch sensor 600 toassociate certain capacitive pads 602 with respective fingers of a useroperating the controller 1500 based on cluster analysis, as describedherein. A cluster analysis module(s) 1524 may implement the clusteranalysis described herein to dynamically determined controllerconfigurations on-the-fly, at runtime, such as by generating thecovariance matrix 800, deriving the feature vectors, and clustering thefeature vectors to determine a controller configuration 1522.

Although the subject matter has been described in language specific tostructural features, it is to be understood that the subject matterdefined in the appended claims is not necessarily limited to thespecific features described. Rather, the specific features are disclosedas illustrative forms of implementing the claims.

What is claimed is:
 1. A system comprising: a handheld controller havinga touch sensor array that includes a plurality of capacitive padsdistributed on a handle of the handheld controller; one or moreprocessors; and one or more non-transitory computer-readable mediastoring computer-executable instructions that, when executed by the oneor more processors, cause the one or more processors to perform actscomprising: receiving, from the touch sensor array, capacitance valuesdetected by the plurality of capacitive pads; generating, based at leastin part on the capacitance values, a covariance matrix that indicatescorrelations between pairs of pads of the plurality of capacitive pads;determining, based at least in part on the covariance matrix, aplurality of feature vectors, each feature vector corresponding to a padof the plurality of capacitive pads and describing a correlation betweenthe pad and one or more other pads of the plurality of capacitive pads;clustering the plurality of feature vectors using a clusteringalgorithm; and configuring the touch sensor array of the handheldcontroller according to a controller configuration based at least inpart on the clustering, the controller configuration assigning at leasta first subset of the plurality of capacitive pads to a first group thatcorresponds to a first finger of a hand and a second subset of theplurality of capacitive pads to a second group that corresponds to asecond finger of the hand.
 2. The system of claim 1, wherein: theplurality of capacitive pads comprises a set of n pads, where n is afirst integer; the generating of the covariance matrix comprisesgenerating the covariance matrix as a n×d covariance matrix based atleast in part on a subset of d reference pads among the plurality ofcapacitive pads, where d is a second integer less than the firstinteger; and the determining of the plurality of feature vectorscomprises determining n d-dimensional feature vectors.
 3. The system ofclaim 2, wherein: the plurality of capacitive pads are distributed onthe handle in rows and columns of pads, the rows oriented substantiallyhorizontally on the handle and the columns oriented substantiallyvertically on the handle; and the subset of d reference pads comprises acolumn of pads.
 4. The system of claim 2, wherein: the clusteringalgorithm is a k-means clustering algorithm; and the clustering of theplurality of feature vectors comprises: initializing the k-meansclustering algorithm with input parameters that include: a number of kclusters; and center estimates for the k clusters in d-dimensionalspace; assigning each feature vector of the plurality of feature vectorsto a cluster of the k clusters that has a center estimate that is asmallest distance from the feature vector; and updating each centerestimate to obtain k updated cluster centers, wherein a center estimatefor a cluster is updated based at least in part on the feature vectorsassigned the cluster.
 5. A method, comprising: receiving data generatedby a plurality of sensors of a touch sensor array of a handheldcontroller, the plurality of sensors distributed on a handle of thehandheld controller; generating, based at least in part on the data, acovariance matrix that indicates correlations between pairs of sensorsof the plurality of sensors; determining, based at least in part on thecovariance matrix, a plurality of feature vectors, each feature vectorcorresponding to a sensor of the plurality of sensors and describing acorrelation between the sensor and one or more other sensors of theplurality of sensors; clustering the plurality of feature vectors usinga clustering algorithm; and configuring the touch sensor array of thehandheld controller according to a controller configuration based atleast in part on the clustering, the controller configuration assigningat least a first subset of the plurality of sensors to a first groupthat corresponds to a first finger of a hand and a second subset of theplurality of sensors to a second group that corresponds to a secondfinger of the hand.
 6. The method of claim 5, wherein: the plurality ofsensors comprises a set of n sensors, where n is a first integer; thegenerating of the covariance matrix comprises generating the covariancematrix as a n×d covariance matrix based at least in part on a subset ofd reference sensors among the plurality of sensors, where d is a secondinteger less than the first integer; and the determining of theplurality of feature vectors comprises determining n d-dimensionalfeature vectors.
 7. The method of claim 6, wherein: the plurality ofsensors are distributed on the handle in rows and columns of sensors,the rows oriented substantially horizontally on the handle and thecolumns oriented substantially vertically on the handle; and the subsetof d reference sensors comprises a column of sensors.
 8. The method ofclaim 6, wherein: the clustering algorithm is a k-means clusteringalgorithm; and the clustering of the plurality of feature vectorscomprises: initializing the k-means clustering algorithm with inputparameters that include: a number of k clusters; and center estimatesfor the k clusters in d-dimensional space; assigning each feature vectorof the plurality of feature vectors to a cluster of the k clusters thathas a center estimate that is a smallest distance from the featurevector; and updating each center estimate to obtain k updated clustercenters, wherein a center estimate for a cluster is updated based atleast in part on the feature vectors assigned the cluster.
 9. The methodof claim 8, wherein the clustering of the plurality of feature vectorsfurther comprises repeating the assigning and the updating until theupdated cluster centers converge to final cluster centers.
 10. Themethod of claim 8, wherein: k=3; and the controller configurationassigns: the first subset of the plurality of sensors to the first groupthat corresponds to the first finger of the hand, the first fingercorresponding to a middle finger; the second subset of the plurality ofsensors to the second group that corresponds to the second finger of thehand, the second finger corresponding to a ring finger; and a thirdsubset of the plurality of sensors to a third group that corresponds toa third finger of the hand, the third finger corresponding to a pinkyfinger.
 11. The method of claim 8, wherein: k=4; and the controllerconfiguration assigns: the first subset of the plurality of sensors tothe first group that corresponds to the first finger of the hand, thefirst finger corresponding to a middle finger; the second subset of theplurality of sensors to the second group that corresponds to the secondfinger of the hand, the second finger corresponding to a ring finger; athird subset of the plurality of sensors to a third group thatcorresponds to a third finger of the hand, the third fingercorresponding to a pinky finger; and a fourth subset of the plurality ofsensors to a fourth group that corresponds to a non-finger group. 12.The method of claim 5, further comprising: determining that at least oneof the first subset or the second subset includes a number of sensorsthat do not satisfy a threshold number of sensors; and refraining fromsending data generated by the at least one of the first subset or thesecond subset to an application configured to receive data generated bythe touch sensor array as input.
 13. The method of claim 5, furthercomprising: determining that at least one of the first subset or thesecond subset includes a non-adjacent sensor that is not adjacent to anyother sensor of the at least one of the first subset or the secondsubset; and refraining from sending data generated by the non-adjacentsensor to an application configured to receive data generated by thetouch sensor array as input.
 14. The method of claim 5, furthercomprising: selecting a predetermined number of sensors from at leastone of the first subset or the second subset as selected sensors thatare to be utilized with an application configured to receive datagenerated by the touch sensor array as input; and refraining fromsending, to the application, data generated by remaining sensors thatare not included in the selected sensors.
 15. A system comprising: ahandheld controller having a touch sensor array that includes aplurality of sensors spread about a handle of the handheld controller;and logic configured to: receive data generated by the plurality ofsensors; generate, based at least in part on the data, a covariancematrix that indicates correlations between pairs of sensors of theplurality of sensors; determine, based at least in part on thecovariance matrix, a plurality of feature vectors, each feature vectorcorresponding to a sensor of the plurality of sensors and describing acorrelation between the sensor and one or more other sensors of theplurality of sensors; cluster the plurality of feature vectors using aclustering algorithm; and configure the touch sensor array of thehandheld controller according to a controller configuration based atleast in part on the clustering, the controller configuration assigningat least a first subset of the plurality of sensors to a first groupthat corresponds to a first finger of a hand and a second subset of theplurality of sensors to a second group that corresponds to a secondfinger of the hand.
 16. The system of claim 15, wherein: the clusteringalgorithm is a k-means clustering algorithm that is initialized withinput parameters that include: a number of k clusters; and centerestimates for the k clusters; and the controller configuration assigns ksubsets of the plurality of sensors to k groups, the k subsetsincluding: the first subset of the plurality of sensors assigned to thefirst group that corresponds to the first finger of the hand, the firstfinger corresponding to a middle finger; the second subset of theplurality of sensors assigned to the second group that corresponds tothe second finger of the hand, the second finger corresponding to a ringfinger; and a third subset of the plurality of sensors assigned to athird group that corresponds to a third finger of the hand, the thirdfinger corresponding to a pinky finger.
 17. The system of claim 16,wherein the k subsets further include a fourth subset of the pluralityof sensors assigned to a fourth group that corresponds to a non-fingergroup.
 18. The system of claim 15, wherein: receiving the data comprisesreceiving the data over a period of time; and generating the covariancematrix comprises: calculating statistics based at least in part on thedata received over the period of time; determining covariance valuesbetween the pairs of sensors based at least in part on the statistics;and populating the covariance matrix with the covariance values.
 19. Thesystem of claim 18, wherein the covariance values are values that rangefrom negative one to positive one.
 20. The system of claim 15, whereinthe logic is further configured to: select a predetermined number ofsensors from at least one of the first subset or the second subset asselected sensors that are to be utilized with an application configuredto receive data generated by the touch sensor array as input; andrefrain from sending, to the application, data generated by remainingsensors that are not included in the selected sensors.